A066742 Square numbers not divisible by 10 whose reverse is pentagonal.

0, 1, 529, 1089, 2116, 6241, 103041, 26222944225, 2648772525025, 6262611355441, 62443279235236, 1520130841269290490409

Offset

1,3

Links

Table of n, a(n) for n=1..12.

Example

925 is pentagonal and 529 is square

Mathematica

dtn[L_] := Fold[10#1+#2&, 0, L] A={0}; For[i=1, i>0, i++, t=i(3i-1)/2; r=dtn[Reverse[IntegerDigits[t]]]; If[IntegerQ[Sqrt[r]]&&Mod[t, 10]>0, AppendTo[A, r]; Print[A]]]

Crossrefs

Sequence in context: A020289 A274932 A082409 * A067475 A052074 A112079

Adjacent sequences: A066739 A066740 A066741 * A066743 A066744 A066745

Keyword

base,more,nonn

Author

Erich Friedman, Jan 16 2002

Extensions

Description clarified, offset corrected, and a(12) added by Lars Blomberg, May 29 2011

Status

approved