A245361 Numbers n such that (reversal of digits of n) + 1 is a square (ignoring leading zeros).

3, 8, 30, 36, 42, 51, 53, 80, 84, 99, 300, 323, 341, 360, 384, 387, 420, 422, 426, 510, 530, 552, 575, 576, 591, 800, 825, 827, 840, 861, 882, 990, 993, 998, 3000, 3032, 3069, 3072, 3201, 3230, 3264, 3276, 3410, 3441, 3477, 3483, 3600, 3633, 3648, 3671, 3806

Offset: 1

Author

K. D. Bajpai, Jul 18 2014

Keywords

• nonn
• base

Comments

(Reversal of digits of prime p) plus 1 is square is given in A167217.

Examples

			84 is in the sequence because reversal of its digits is 48 and 48 + 1 = 49 = 7^2.
510 is in the sequence because reversal of its digits is 15 and 15 + 1 = 16 = 4^2.
		

Links

• K. D. Bajpai, Table of n, a(n) for n = 1..6696

Crossrefs

Cf. A000290, A061230, A061457, A167217.

Programs

Mathematica

Select[Range[10^4],IntegerQ[Sqrt[FromDigits[Reverse[IntegerDigits[#]]] + 1]] &]

PARI

revint(n) = eval(concat(Vecrev(Str(n))))
select(n->issquare(revint(n)+1), vector(4000, n, n)) \\ Colin Barker, Jul 20 2014