A066618 Both m and its reverse are one more than a square and m does not end in 0.

1, 2, 5, 101, 626, 5477, 7745, 10001, 1000001, 1010026, 1040401, 2217122, 2676497, 5053505, 6200101, 7946762, 100000001, 101808101, 10000000001, 10180608202, 10182828101, 10408080401, 20280608101, 26573890226, 26995147205

Offset: 1

Author

Erich Friedman, Jan 08 2002

Keywords

• nonn
• base

Examples

			7745 = 88^2 + 1 and 5477 = 74^2 + 1.
		

Links

• Harry J. Smith, Table of n, a(n) for n = 1..53

Programs

Mathematica

dtn[L_] := Fold[10#1+#2&, 0, L] A={}; For[i=1, i>0, i++, t=dtn[Reverse[IntegerDigits[i^2+1]]]; If[IntegerQ[(t-1)^(1/2)]&&Mod[i^2, 10]=!=9, AppendTo[A, i^2+1]; Print[A]]]

PARI

Rev(x)= { local(d, r=0); while (x>0, d=x%10; x\=10; r=r*10 + d); return(r) } { n=0; for (m=0, 10^10, k=m^2 + 1; if (k%10 && issquare(Rev(k) - 1), write("b066618.txt", n++, " ", k); if (n==100, return)) ) } \\ Harry J. Smith, Mar 13 2010