A113799 - OEIS

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A113799

Numbers n such that the n-th triangular number plus the reverse of n gives a square.

3, 36, 45, 423, 486, 558, 1377, 6690, 15540, 59460, 110694, 16867050, 443820753 (list; graph; refs; listen; history; internal format)

	OFFSET	`1,1`
	EXAMPLE	`T(423)+324=300^2.`
	MATHEMATICA	`testQ[n_] := IntegerQ[Sqrt[n(n+1)/2 + FromDigits@Reverse@IntegerDigits@n]]; lst = Select[Range[10^5], testQ]`
	CROSSREFS	`Sequence in context: A189216 A158301 A105758 * A072682 A158207 A153448` `Adjacent sequences: A113796 A113797 A113798 * A113800 A113801 A113802`
	KEYWORD	`base,nonn`
	AUTHOR	`Giovanni Resta (g.resta(AT)iit.cnr.it), Jan 22 2006`

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Last modified February 17 09:07 EST 2012. Contains 206000 sequences.