login
This site is supported by donations to The OEIS Foundation.
Logo

Hints
(Greetings from The On-Line Encyclopedia of Integer Sequences!)
A126204 Least prime representable as the arithmetic mean of two other primes in n different ways. 3
2, 5, 11, 17, 37, 53, 89, 71, 101, 179, 137, 193, 233, 257, 251, 401, 311, 373, 347, 457, 661, 479, 547, 599, 617, 641, 683, 907, 881, 773, 827, 809, 941, 1033, 977, 1289, 1201, 1187, 1229, 1223, 1277, 1361, 1597, 1493, 1447, 1499, 1451, 1549, 1487, 1709, 1933 (list; graph; refs; listen; history; internal format)
OFFSET

0,1

COMMENTS

a(n)=A000040(A137700(n)); A071681(A137700(n))=n and A071681(m)<>n for m < A137700(n). - Reinhard Zumkeller (reinhard.zumkeller(AT)gmail.com), Feb 07 2008

LINKS

Robert G. Wilson, v, Table of n, a(n) for n=0..11300.<br>

MATHEMATICA

f[n_] := Block[{c = 0, k = PrimePi@n - 1}, While[k > 0, If[ PrimeQ[2n - Prime@k], c++ ]; k-- ]; c]; t = Table[0, {1000}]; Do[ p = Prime@n; a = f@p; If[a < 1001 && t[[a]] == 0, t[[a]] = p; Print[{a, p}]], {n, 8900}]

CROSSREFS

Cf. A071681.

Sequence in context: A059987 A027426 A133928 * A091936 A153145 A174003

Adjacent sequences:  A126201 A126202 A126203 * A126205 A126206 A126207

KEYWORD

nonn

AUTHOR

Robert G. Wilson v (rgwv(AT)rgwv.com), Mar 22 2007

EXTENSIONS

Start of b-file modified to match sequence by N. J. A. Sloane, Aug 31 2009

Lookup | Welcome | Wiki | Register | Music | Plot 2 | Demos | Index | Browse | More | WebCam
Contribute new seq. or comment | Format | Transforms | Puzzles | Hot | Classics
Recent Additions | More pages | Superseeker | Maintained by The OEIS Foundation Inc.

Content is available under The OEIS End-User License Agreement .

Last modified February 16 15:27 EST 2012. Contains 205930 sequences.