A115442 Numbers whose square is the concatenation of two numbers k and k-2.

8, 7312, 8991, 32524, 67477, 76568, 4891730, 5108271, 8528094, 71588336, 98999901, 399659933007, 600340066994, 723627738227, 877712329768, 998999999001, 3485626998114, 3787100274614, 6212899725387, 6514373001887

Offset: 1

Author

Giovanni Resta, Jan 24 2006

Keywords

• base
• nonn

Examples

			8083_8081 = 8991^2.
		

Crossrefs

Cf. A030467, A106497, A115431, A115427, A115438, A115439, A115440, A115441, A115443, A115444, A115445, A115446, A115447.

Programs

Mathematica

Select[Table[Sqrt[k*10^IntegerLength[k]+k-2],{k,4,86*10^5}],IntegerQ] (* The program generates the first 9 terms of the sequence. *) (* Harvey P. Dale, Nov 02 2024 *)