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%I #16 Nov 05 2023 13:57:02
%S 0,1,925,1426,6112,9801,140301,52244922262,1445531162626,
%T 5205252778462,63253297234426,9040940929621480310251
%N Pentagonal numbers not divisible by 10 whose reverse is a square.
%C a(13) > 2^63. - Donovan Johnson, May 24 2011
%e 925 is pentagonal and 529 is square
%t 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, t]; Print[A]]]
%Y Cf. A000326.
%K base,more,nonn
%O 1,3
%A _Erich Friedman_, Jan 16 2002
%E a(12) from _Donovan Johnson_, Apr 03 2008
%E Offset corrected by _Donovan Johnson_, May 24 2011
%E Description clarified and a(12) corrected by _Lars Blomberg_, May 29 2011