A087916 Number of ordered ways to write 2n+1 as a sum of 3 odd primes.

0, 0, 0, 0, 1, 3, 6, 7, 9, 12, 16, 18, 21, 27, 30, 30, 34, 36, 42, 46, 48, 48, 51, 63, 60, 64, 81, 75, 76, 87, 87, 90, 102, 105, 97, 117, 114, 105, 144, 129, 126, 159, 141, 145, 177, 162, 160, 195, 186, 153, 207, 201, 171, 237, 210, 187, 255, 234, 222, 279

Offset

0,6

Links

T. D. Noe, Table of n, a(n) for n = 0..10000

Mathematica

nn = 100; lim = 2*nn + 17; ps = Prime[Range[2, nn + 1]]; t = Table[0, {lim}]; Do[s = i + j + k; If[s <= lim, t[[s]]++], {i, ps}, {j, ps}, {k, ps}]; Take[t, {1, lim, 2}] (* T. D. Noe, Apr 10 2014 *)

Prog

(PARI) for(n=0, 100, t=2*n+1; c=0; for(k=2, t, for(l=2, t, for(m=2, t, tt=prime(k)+prime(l)+prime(m); if(tt>2*n+1, break); if(tt==2*n+1, c=c+1)))); print1(c", "))

Crossrefs

Cf. A007963 (unordered), A068307 (with 2).

Cf. A087917.

Sequence in context: A325443 A085359 A231664 * A359263 A296693 A282585

Adjacent sequences: A087913 A087914 A087915 * A087917 A087918 A087919

Keyword

nonn,easy

Author

Ralf Stephan, Oct 18 2003

Extensions

Leading zeros added by T. D. Noe, Apr 10 2014

Status

approved