A133322 Centered square numbers that are prime powers of the form (4n+1)^k.

5, 13, 25, 41, 61, 113, 181, 313, 421, 613, 761, 841, 1013, 1201, 1301, 1741, 1861, 2113, 2381, 2521, 3121, 3613, 4513, 5101, 7321, 8581, 9661, 9941, 10513, 12641, 13613, 14281, 14621, 15313, 16381, 19013, 19801, 20201, 21013, 21841, 23981

Offset

1,1

Links

Table of n, a(n) for n=1..41.

Mathematica

a = {}; For[i = 1, i < 140, i++, k = 1; b = (2*i*(i + 1) + 1); While[b^(1/k) > 4, If[PrimeQ[b^(1/k)], If[Mod[b^(1/k), 4] == 1, AppendTo[a, b]]]; k++ ]]; a (* Stefan Steinerberger, Oct 21 2007 *)

Crossrefs

Subsequence of A001844 and A120960.

Sequence in context: A001844 A099776 A301302 * A299258 A301671 A268525

Adjacent sequences: A133319 A133320 A133321 * A133323 A133324 A133325

Keyword

nonn

Author

Mats Granvik, Oct 18 2007, Oct 19 2007

Extensions

More terms from Stefan Steinerberger, Oct 21 2007

Status

approved