A225675 Numbers n such that triangular(n) is representable as p*w, where p is a prime number and w is a prime power (A025475).

2, 7, 9, 16, 17, 18, 25, 26, 31, 53, 81, 97, 121, 127, 162, 241, 250, 256, 337, 361, 486, 577, 625, 841, 1249, 1458, 2186, 2401, 2662, 3361, 3481, 3697, 3721, 4373, 4801, 5041, 6241, 6961, 8191, 10201, 10657, 13121, 14641, 17161, 19321, 23761, 25537, 28561, 31249, 32257

Offset

1,1

Comments

Corresponding triangular numbers are in A225674.

The subsequence of even terms begins: 2, 16, 18, 26, 162, 250, 256, 486, 1458, 2186, 2662, 39366, 48778, 65536, 410758, 715822, 1594322, 2450086, 6615898, 12872686, 13935742, 15290746, 23394166, 38930218, 41022298, 86093442, ...

Links

Table of n, a(n) for n=1..50.

Crossrefs

Cf. A000040, A000217, A025475, A225674.

Sequence in context: A154789 A106352 A098017 * A185869 A020894 A165995

Adjacent sequences: A225672 A225673 A225674 * A225676 A225677 A225678

Keyword

nonn

Author

Alex Ratushnyak, May 12 2013

Status

approved