A115711 Squares whose digit reversal is a semiprime (A001358).

4, 9, 49, 64, 121, 169, 289, 400, 625, 900, 961, 1156, 1225, 1849, 2401, 3136, 3364, 3481, 3721, 4900, 5041, 5329, 6400, 6889, 7396, 9604, 10201, 10816, 11449, 11881, 12100, 12544, 12769, 13225, 13456, 13924, 15376, 15625, 16129, 16384, 16900

Offset

1,1

Links

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

Example

64=8^2 and 46=2*23 is semiprime.

Mathematica

Select[Range[150]^2, PrimeOmega[FromDigits[Reverse[ IntegerDigits[ #]]]]==2&] (* Harvey P. Dale, Sep 20 2011 *)

Crossrefs

Cf. A001358, A115710.

Sequence in context: A225885 A247267 A115687 * A029791 A053961 A055812

Adjacent sequences: A115708 A115709 A115710 * A115712 A115713 A115714

Keyword

nonn,base

Author

Giovanni Resta, Jan 31 2006

Status

approved