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In binary expansion of n-th prime: reduce contiguous blocks of 0's to 0 and contiguous blocks of 1's to 1.
(history; published version)

#3 by Russ Cox at Fri Mar 30 18:50:42 EDT 2012

AUTHOR

_Reinhard Zumkeller (reinhard.zumkeller(AT)gmail.com), _, Nov 20 2003

Discussion

Fri Mar 30

18:50

OEIS Server: https://oeis.org/edit/global/246

#2 by N. J. A. Sloane at Fri Jan 09 03:00:00 EST 2009

KEYWORD

nonn,base,new

AUTHOR

Reinhard Zumkeller (reinhard.zumkeller(AT)lhsystemsgmail.com), Nov 20 2003

#1 by N. J. A. Sloane at Thu Feb 19 03:00:00 EST 2004

NAME

In binary expansion of n-th prime: reduce contiguous blocks of 0's to 0 and contiguous blocks of 1's to 1.

DATA

2, 1, 5, 1, 5, 5, 5, 5, 5, 5, 1, 21, 21, 21, 5, 21, 5, 5, 5, 5, 21, 5, 21, 21, 5, 21, 5, 21, 21, 5, 1, 5, 21, 21, 85, 21, 21, 21, 21, 85, 21, 85, 5, 5, 21, 5, 21, 5, 5, 21, 21, 5, 5, 5, 5, 5, 21, 5, 85, 21, 21, 85, 21, 21, 21, 21, 85, 85, 85, 85, 21, 21, 21, 85, 21, 5, 21, 21, 21

OFFSET

1,1

COMMENTS

a(n) = A090079(A000040(n)).

EXAMPLE

A000040(25)=97 -> '1100001' -> [11][0000][1] -> [1][0][1] ->

'101' -> 5=a(25).

CROSSREFS

Cf. A004676.

KEYWORD

nonn,base

AUTHOR

Reinhard Zumkeller (reinhard.zumkeller(AT)lhsystems.com), Nov 20 2003

STATUS

approved