A115761 Numbers k such that the digits of k^2, reversed, include the digits of k as a substring.

1, 5, 6, 27, 74, 963, 5723, 6142, 6524, 9867, 53152, 65766, 69714, 351732, 409761, 497674, 624279, 664902, 697140, 781101, 2733747, 3879405, 4897317, 5031485, 6317056, 6971400, 8403702, 9324454, 16013465, 21646858, 34679962, 36909226, 38794051, 40781862, 41065012

Offset: 1

Author

Giovanni Resta, Jan 30 2006

Keywords

• nonn
• base

Examples

			963^2 = 927(369).
		

Links

• Giovanni Resta, Table of n, a(n) for n = 1..97 (terms < 4*10^12)

Crossrefs

Contains A269588 as a subsequence.

Cf. A115762, A115763, A115764, A115738, A179803.

Programs

Mathematica

fQ[n_] := StringPosition[ IntegerString[n^2], StringReverse@ IntegerString@n] != {}; k = 1; lst = {}; While[k < 38794050, If[ fQ@k, AppendTo[lst, k]]; k++ ]; lst (* Robert G. Wilson v, Jul 28 2010 *)
Select[Range[37*10^6],SequenceCount[Reverse[IntegerDigits[#^2]], IntegerDigits[ #]]>0&] (* The program uses the SequenceCount function from Mathematica version 10 *) (* Harvey P. Dale, May 02 2016 *)

Extensions

More terms from Robert G. Wilson v, Jul 28 2010

Terms a(33) and beyond from Giovanni Resta, May 04 2020