A115710 Semiprimes (A001358) whose digit reversal is a square.

4, 9, 10, 46, 94, 121, 169, 526, 961, 982, 1042, 1273, 1405, 1843, 4069, 4633, 5221, 6313, 6511, 6937, 9235, 9481, 9886, 10201, 10609, 12538, 12769, 14023, 16171, 16327, 16582, 16723, 18085, 18463, 18811, 40219, 42817, 42931, 44353, 44521

Offset

1,1

Links

Table of n, a(n) for n=1..40.

Example

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

Mathematica

Select[Range[50000], PrimeOmega[#]==2&&IntegerQ[Sqrt[FromDigits[ Reverse[ IntegerDigits[ #]]]]]&] (* Harvey P. Dale, Mar 03 2013 *)

Crossrefs

Cf. A001358, A115711.

Sequence in context: A197125 A197129 A115688 * A082749 A220427 A115675

Adjacent sequences: A115707 A115708 A115709 * A115711 A115712 A115713

Keyword

nonn,base

Author

Giovanni Resta, Jan 31 2006

Status

approved