A085263 - OEIS

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A085263

Number of ways to write n as sum of a squarefree number and a square.

0, 1, 1, 1, 1, 2, 2, 1, 1, 2, 3, 2, 0, 3, 3, 2, 2, 3, 3, 2, 2, 3, 4, 2, 1, 4, 4, 2, 1, 5, 4, 3, 2, 2, 5, 2, 3, 6, 6, 3, 2, 6, 4, 3, 2, 5, 6, 3, 2, 5, 6, 3, 2, 4, 6, 4, 3, 4, 6, 4, 1, 7, 5, 3, 3, 7, 6, 4, 4, 6, 8, 3, 3, 6, 7, 2, 4, 8, 5, 4, 3, 7, 9, 4, 2, 8, 9, 4, 3, 6, 6, 5, 4, 7, 9, 5, 3, 8, 4, 3, 5, 9 (list; graph; refs; listen; history; internal format)

	OFFSET	`1,6`
	COMMENTS	`a(A085265(n))>0; a(A085266(n))=1; a(A085267(n))>1.` `a(A085264(n))=n and a(i)<>n for i < A085264(n).`
	LINKS	`T. D. Noe, Table of n, a(n) for n = 1..10000` `Eric Weisstein's World of Mathematics, Square Numbers.` `Eric Weisstein's World of Mathematics, Squarefree`
	FORMULA	`a(n+1) = SUM(A008966(k)*A010052(n-k+1): 1<=k<=n). [From Reinhard Zumkeller (reinhard.zumkeller(AT)gmail.com), Nov 04 2009]`
	EXAMPLE	`a(11)=3: 11 = 1+10=A000290(1)+A005117(7) =` `4+7=A000290(2)+A005117(6) = 9+2=A000290(3)+A005117(2).`
	CROSSREFS	`Sequence in context: A030298 A098281 A103343 * A115092 A172281 A176298` `Adjacent sequences: A085260 A085261 A085262 * A085264 A085265 A085266`
	KEYWORD	`nonn`
	AUTHOR	`Reinhard Zumkeller (reinhard.zumkeller(AT)gmail.com), Jun 23 2003`

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Last modified February 16 11:47 EST 2012. Contains 205907 sequences.