The On-Line Encyclopedia of Integer Sequences (OEIS)

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Revision History for A074116

(Bold, blue-underlined text is an addition; faded, red-underlined text is a ~~deletion~~.)
Showing entries 1-10 | older changes

A074116

Largest n-digit power of 2.
(history; published version)

#18 by N. J. A. Sloane at Wed Jan 18 22:35:42 EST 2017

STATUS

editing

approved

#17 by N. J. A. Sloane at Wed Jan 18 22:35:40 EST 2017

FORMULA

a(n) = 2^A066343(n). - _Evgeny Kapun_, Jan 16 2017

STATUS

approved

editing

#16 by N. J. A. Sloane at Wed Jan 18 22:34:44 EST 2017

STATUS

editing

approved

#15 by N. J. A. Sloane at Wed Jan 18 22:34:42 EST 2017

COMMENTS

This sequence is the same as A074113. - Evgeny Kapun, Jan 16 2017

An equivalent definition (which was formerly the definition of A074113): "Smallest n-digit number of the form p^a*q^b... with the maximum value of a+b+.... where p, q etc. are primes. If a,b,c,... are the indices in the signature prime factorization then a+b+c ... is a maximum." That this is the same sequence follows from the inequality p^a*q^b... >= 2^(a+b+...) and the fact that there always exists a power of 2 between two consecutive powers of 10.

CROSSREFS

Cf. A066343, A067488, A074113, A074114, A074117, A074118.

EXTENSIONS

More terms from _Edited by _R. J. Mathar_, Feb 13 2008, _Max Alekseyev_, Mar 10 2009, _Harvey P. Dale_, Jul 17 2011, _Evgeny Kapun_, Jan 16 2017, and _N. J. A. Sloane_, Jan 18 2017

Edited by Evgeny Kapun, Jan 16 2017

To be declared "dead"

STATUS

approved

editing

#14 by N. J. A. Sloane at Wed Jan 18 22:28:56 EST 2017

STATUS

editing

approved

#13 by N. J. A. Sloane at Wed Jan 18 22:28:51 EST 2017

DATA

8, 64, 512, 8192, 65536, 524288, 8388608, 67108864, 536870912, 8589934592, 68719476736, 549755813888, 8796093022208, 70368744177664, 562949953421312, 9007199254740992, 72057594037927936, 576460752303423488, 9223372036854775808, 73786976294838206464, 590295810358705651712

#12 by N. J. A. Sloane at Wed Jan 18 22:25:37 EST 2017

EXTENSIONS

To be declared "dead"

STATUS

approved

editing

Discussion

Wed Jan 18

22:25

N. J. A. Sloane: I will handle this!

22:28

N. J. A. Sloane: Sorry, it is A074113 that will be declared dead, not this one

#11 by N. J. A. Sloane at Wed Jan 18 22:25:17 EST 2017

STATUS

proposed

approved

#10 by Jon E. Schoenfield at Mon Jan 16 10:19:43 EST 2017

STATUS

editing

proposed

Discussion

Mon Jan 16

10:21

Jon E. Schoenfield: @Editors -- if this sequence is identical to A074113, should this one be given keyword:dead?

10:25

Joerg Arndt: If these two are identical then let's kill A074113, as it is the horriblerer of them.

12:59

Jon E. Schoenfield: What's the procedure for euthanizing the more horriblerer one?  :-) Is it a matter of deciding which parts (if any) are sufficiently nonhorrible should be cut out of it and grafted into its less-horribility-enhanced duplicate sequence?

#9 by Jon E. Schoenfield at Mon Jan 16 10:19:04 EST 2017

COMMENTS

This sequence is the same as A074113. _- _Evgeny Kapun_, Jan 16 2017

The exponents are given in A066343. _- _Evgeny Kapun_, Jan 16 2017

FORMULA

a(n) = 2^A066343(n). _- _Evgeny Kapun_, Jan 16 2017

EXTENSIONS

More terms from _Harvey P. Dale, _, Jul 17 2011

Discussion

Mon Jan 16

10:19

Jon E. Schoenfield: attribution format corrections