A179889 Triangular numbers whose reverse is a square (possibly with fewer digits).

1, 10, 630, 52650, 165600, 986310, 9446031, 9485190, 10693000, 1270004401, 14214075921, 140884670790, 1809702709101, 4614899724711, 6766532724546, 9802814901400, 10210140486640, 14287075542460, 52657436563056, 98855178542676

Offset: 1

Author

Harvey P. Dale, Jan 30 2011

Keywords

• base
• nonn

Examples

			9446031 is triangular and 1306449 is a square.
		

Links

• Giovanni Resta, Table of n, a(n) for n = 1..36 (terms < 2*10^24)

Crossrefs

A variant of A066703. Cf. A069673, A181412, A066528.

Programs

Mathematica

trnos=Accumulate[Range[14070000]];
sqnoQ[n_]:=IntegerQ[Sqrt[FromDigits[Reverse[IntegerDigits[n]]]]]
Select[trnos,sqnoQ]  (* Harvey P. Dale, Jan 31 2011 *)

Extensions

More terms from Harvey P. Dale, Jan 31 2011