A136345 Sums of exactly two positive octagonal numbers A000567.

2, 9, 16, 22, 29, 41, 42, 48, 61, 66, 73, 80, 86, 97, 104, 105, 117, 130, 134, 136, 141, 154, 161, 173, 177, 184, 192, 197, 198, 216, 226, 229, 233, 241, 246, 265, 266, 272, 281, 288, 290, 301, 309, 320, 321, 342, 345, 349, 352, 358, 362, 376, 381, 401, 406, 409

Offset

1,1

Comments

For octagonal numbers within this sequence, see: A136346. This is to octagonal numbers A000567 as A051533 is to triangular numbers A000217 and as A000404 is to squares A000290 and as A117104 is to heptagonal numbers A000566.

Links

Table of n, a(n) for n=1..56.

Eric Weisstein's World of Mathematics, Octagonal Number.

Formula

{A000567(i) + A000567(j), i, j > 0}. {i*(3*i-2) + j(3*j-2), i, j > 0}.

Crossrefs

Cf. A000567, A136117, A136346.

Sequence in context: A162614 A031238 A224859 * A017005 A131189 A288484

Adjacent sequences: A136342 A136343 A136344 * A136346 A136347 A136348

Keyword

easy,nonn

Author

Jonathan Vos Post, Dec 25 2007

Extensions

Missing term (80) from Giovanni Resta, Jun 19 2016

Status

approved