The On-Line Encyclopedia of Integer Sequences (OEIS)

Revision History for A046921 (Bold, blue-underlined text is an addition; faded, red-underlined text is a ~~deletion~~.)
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A046921

Number of ways to express 2n+1 as p+2a^2; p = 1 or prime, a >= 0.
(history; published version)

#18 by Hugo Pfoertner at Thu Jul 22 09:18:25 EDT 2021

STATUS

reviewed

approved

#17 by Joerg Arndt at Thu Jul 22 08:02:39 EDT 2021

STATUS

proposed

reviewed

#16 by Michel Marcus at Thu Jul 22 04:44:38 EDT 2021

STATUS

editing

proposed

#15 by Michel Marcus at Thu Jul 22 04:44:03 EDT 2021

COMMENTS

The only zero terms appear to be for the odd numbers 5777 and 5993. - _T. D. Noe, _, Aug 23 2008

a(n) = A046920(A005408(n)). - Reinhard Zumkeller, Apr 03 2013

LINKS

L. Hodges, <a href="httphttps://learning.physicswww.iastatejstor.eduorg/hodgesstable/mm-1.pdf2690477">A lesser-known Goldbach conjecture</a>, Math. Mag., 66 (1993), 45-47.

FORMULA

a(n) = A046920(A005408(n)). - Reinhard Zumkeller, Apr 03 2013

STATUS

approved

editing

Discussion

Thu Jul 22

04:44

Michel Marcus: link was dead

#14 by Charles R Greathouse IV at Sun Aug 28 18:18:33 EDT 2016

LINKS

T. D. Noe, <a href="/A046921/b046921.txt">Table of n, a(n) for n = 0..10000</a>

Discussion

Sun Aug 28

18:18

OEIS Server: https://oeis.org/edit/global/2560

#13 by Reinhard Zumkeller at Wed Apr 03 09:28:16 EDT 2013

STATUS

editing

approved

#12 by Reinhard Zumkeller at Wed Apr 03 09:10:33 EDT 2013

COMMENTS

a(n) = A046920(A005408(n)). - Reinhard Zumkeller, Apr 03 2013

PROG

(Haskell)

a046921 = a046920 . a005408 -- Reinhard Zumkeller, Apr 03 2013

CROSSREFS

Cf. A007697.

STATUS

approved

editing

#11 by Russ Cox at Fri Mar 30 18:35:36 EDT 2012

AUTHOR

_David W. Wilson (davidwwilson(AT)comcast.net)_

Discussion

Fri Mar 30

18:35

OEIS Server: https://oeis.org/edit/global/202

#10 by Russ Cox at Sun Jul 10 18:42:37 EDT 2011

LINKS

<a href="/Sindx_index/Go.html#Goldbach">Index entries for sequences related to Goldbach conjecture</a>

Discussion

Sun Jul 10

18:42

OEIS Server: https://oeis.org/edit/global/44

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

LINKS

T. D. Noe, <a href="/A046921/b046921.txt">Table of n, a(n) for n=0..10000</a>

<a href="/Sindx_Go.html#Goldbach">Index entries for sequences related to Goldbach conjecture</a>

KEYWORD

nonn,new

nonn