The On-Line Encyclopedia of Integer Sequences (OEIS)

The OEIS is supported by the many generous donors to the OEIS Foundation.

Revision History for A063484

(Bold, blue-underlined text is an addition; faded, red-underlined text is a ~~deletion~~.)
Showing all changes.

Omega(n+1) = 2*Omega(n), where Omega(n) is the number of prime divisors of n (with repetition).
(history; published version)

#10 by N. J. A. Sloane at Fri Dec 15 17:35:22 EST 2017

AUTHOR

_Jason Earls (zevi_35711(AT)yahoo.com), _, Jul 28 2001

Discussion

Fri Dec 15

17:35

OEIS Server: https://oeis.org/edit/global/2722

#9 by Charles R Greathouse IV at Fri Aug 19 00:42:48 EDT 2016

PROG

(PARI) { n=0; for (m=1, 10^9, if (bigomega(m + 1) == 2*bigomega(m), write("b063484.txt", n++, " ", m); if (n==1000, break)) ) } [From _\\ _Harry J. Smith_, Aug 23 2009]

Discussion

Fri Aug 19

00:42

OEIS Server: https://oeis.org/edit/global/2555

#8 by Russ Cox at Fri Mar 30 17:24:24 EDT 2012

PROG

(PARI) { n=0; for (m=1, 10^9, if (bigomega(m + 1) == 2*bigomega(m), write("b063484.txt", n++, " ", m); if (n==1000, break)) ) } [From _Harry J. Smith (hjsmithh(AT)sbcglobal.net), _, Aug 23 2009]

Discussion

Fri Mar 30

17:24

OEIS Server: https://oeis.org/edit/global/133

#7 by N. J. A. Sloane at Thu Nov 11 07:34:06 EST 2010

LINKS

Harry J. Smith, <a href="/A063484/b063484.txt">Table of n, a(n) for n=1,...,1000</a>

KEYWORD

nonn,new

nonn

#6 by N. J. A. Sloane at Tue Jun 01 03:00:00 EDT 2010

LINKS

Harry J. Smith, <a href="b063484.txt">Table of n, a(n) for n=1,...,1000</a>

PROG

(PARI) { n=0; for (m=1, 10^9, if (bigomega(m + 1) == 2*bigomega(m), write("b063484.txt", n++, " ", m); if (n==1000, break)) ) } [From Harry J. Smith (hjsmithh(AT)sbcglobal.net), Aug 23 2009]

KEYWORD

nonn,new

nonn

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

KEYWORD

nonn,new

nonn

AUTHOR

Jason Earls (jcearlszevi_35711(AT)cableoneyahoo.netcom), Jul 28 2001

#4 by N. J. A. Sloane at Wed Sep 22 03:00:00 EDT 2004

KEYWORD

nonn,new

nonn

AUTHOR

Jason Earls (jcearls(AT)4grccableone.comnet), Jul 28 2001

#3 by N. J. A. Sloane at Sat Jun 12 03:00:00 EDT 2004

KEYWORD

nonn,new

nonn

AUTHOR

Jason Earls (jcearls(AT)kskc4grc.netcom), Jul 28 2001

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

PROG

(PARI) j=[]; for(n=1, 1000, if(bigomega(n+1)==2*bigomega(n), j=concat(j, n))); j

KEYWORD

nonn,new

nonn

#1 by N. J. A. Sloane at Fri May 16 03:00:00 EDT 2003

NAME

Omega(n+1) = 2*Omega(n), where Omega(n) is the number of prime divisors of n (with repetition).

DATA

3, 5, 13, 15, 35, 37, 39, 55, 61, 63, 73, 87, 134, 155, 157, 183, 193, 203, 209, 219, 247, 249, 259, 277, 295, 305, 313, 314, 327, 329, 339, 341, 371, 397, 399, 413, 421, 457, 458, 471, 489, 515, 535, 539, 541, 545, 579, 583, 613, 635, 649, 661, 673, 685, 689

OFFSET

1,1

EXAMPLE

Omega(949)=2, Omega(949+1)=2*2, so 949 is a member of the sequence.

PROG

(PARI) j=[]; for(n=1, 1000, if(bigomega(n+1)==2*bigomega(n), j=concat(j, n))); j

KEYWORD

nonn

AUTHOR

Jason Earls (jcearls(AT)kskc.net), Jul 28 2001

STATUS

approved