A117382 Primes not expressible as the sum of two triangular numbers.

5, 17, 19, 23, 41, 47, 53, 59, 71, 89, 103, 107, 109, 113, 131, 149, 167, 173, 179, 197, 223, 229, 233, 239, 251, 257, 269, 271, 283, 293, 311, 313, 317, 337, 347, 349, 359, 383, 397, 401, 419, 431, 439, 449, 457, 467, 479, 491, 503, 509, 521, 523, 547, 557

Offset

0,1

Links

Table of n, a(n) for n=0..53.

Mathematica

Complement[ Prime@ Range@115, Union@ Flatten@ Table[i(i + 1)/2 + j(j + 1)/2, {i, 35}, {j, 0, i}]] (* Robert G. Wilson v, Apr 27 2006 *)

Crossrefs

Cf. A000040, A117112.

Sequence in context: A249589 A040153 A038896 * A191076 A166685 A167915

Adjacent sequences: A117379 A117380 A117381 * A117383 A117384 A117385

Keyword

easy,nonn

Author

Greg Huber, Apr 24 2006

Extensions

More terms from Robert G. Wilson v, Apr 27 2006

Status

approved