A115266 - OEIS

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A115266

Row sums of correlation triangle for floor((n+3)/3).

1, 2, 4, 8, 13, 20, 31, 44, 61, 84, 111, 144, 186, 234, 291, 360, 438, 528, 634, 752, 886, 1040, 1210, 1400, 1615, 1850, 2110, 2400, 2715, 3060, 3441, 3852, 4299, 4788, 5313, 5880, 6496, 7154, 7861, 8624, 9436, 10304, 11236, 12224, 13276, 14400, 15588 (list; graph; refs; listen; history; internal format)

	OFFSET	`0,2`
	COMMENTS	`Row sums of number triangle A115265.`
	FORMULA	`G.f.: (1+x+x^2)^2/((1-x^3)^4(1-x^2)); a(n)=sum{k=0..n, sum{j=0..n, [j<=k]floor((k-j+3)/3)[j<=n-k]floor((n-k-j+3)/3)}}.`
	CROSSREFS	`Sequence in context: A173721 A061866 A130840 * A026039 A004978 A005282` `Adjacent sequences: A115263 A115264 A115265 * A115267 A115268 A115269`
	KEYWORD	`easy,nonn`
	AUTHOR	`Paul Barry (pbarry(AT)wit.ie), Jan 18 2006`

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Last modified February 16 21:51 EST 2012. Contains 205978 sequences.