A124660 a(n) = Sum_{k=1..n-2} ( prime(n+k)/2 + prime(n-k)/2 - prime(n) ).

0, 2, -1, 5, 4, 16, 17, 3, 24, 6, 9, 42, 50, 27, 10, 56, 40, 59, 119, 103, 130, 110, 50, 83, 167, 204, 302, 349, 102, 141, 130, 243, 103, 233, 225, 219, 287, 282, 277, 437, 273, 438, 524, 700, 428, 148, 236, 427, 532, 548, 772, 580, 598, 614, 628, 864, 884, 1018, 1274, 1053

Offset

3,2

Links

Table of n, a(n) for n=3..62.

Maple

A124660 := proc(n) add( (ithprime(n+k)+ithprime(n-k))/2-ithprime(n), k=1..n-2) ; end proc:
seq(A124660(n), n=3..80) ; # R. J. Mathar, Mar 28 2010

Mathematica

Table[Sum[Prime[n+k]/2+Prime[n-k]/2-Prime[n], {k, n-2}], {n, 3, 62}] (* James C. McMahon, Dec 14 2024 *)

Crossrefs

Sequence in context: A309976 A257516 A346800 * A217104 A141485 A005605

Adjacent sequences: A124657 A124658 A124659 * A124661 A124662 A124663

Keyword

sign,easy,changed

Author

Artur Jasinski, Dec 23 2006

Extensions

Offset corrected and sequence extended by R. J. Mathar, Mar 28 2010

Status

approved