id:A101159 - OEIS Search Results

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Let j be the smallest integer for which n+(n+1)+...+(n+j) is a square; then a(n) = n+j.

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4

1, 4, 7, 4, 13, 16, 19, 22, 9, 28, 13, 13, 37, 40, 43, 16, 49, 22, 55, 58, 28, 64, 67, 25, 25, 28, 79, 82, 85, 88, 91, 40, 97, 100, 40, 36, 44, 112, 49, 41, 121, 124, 47, 130, 53, 58, 49, 142, 49, 148 (list; graph; listen)

	OFFSET	`1,2`
	COMMENT	`Basis for sequence is shortest arithmetic sequence with initial term n and difference 1 that sums to a perfect square. Cf. A100251-A100254.`
	FORMULA	`n+(n+1)+...+(n+A101160(n))=n+(n+1)+...+A101159(n)= A101157(n)^2=A101158(n)`
	EXAMPLE	`a(11)=13 since j=13 is the smallest integer such that 11+...+j=6^2=36 is a perfect square.`
	CROSSREFS	`Cf. A101157-A101160.` `Sequence in context: A059139 A110669 A106027 this_sequence A166530 A011518 A132265` `Adjacent sequences: A101156 A101157 A101158 this_sequence A101160 A101161 A101162`
	KEYWORD	`nonn`
	AUTHOR	`Charlie Marion (charliemath(AT)optonline.net), Dec 29 2004`

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Last modified March 20 01:21 EDT 2010. Contains 173643 sequences.

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