id:A089048 - OEIS Search Results

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Number of ways of writing n as a sum of exactly 3 powers of 2.

+0
4

0, 0, 0, 1, 1, 1, 2, 1, 1, 1, 2, 1, 2, 1, 1, 0, 1, 1, 2, 1, 2, 1, 1, 0, 2, 1, 1, 0, 1, 0, 0, 0, 1, 1, 2, 1, 2, 1, 1, 0, 2, 1, 1, 0, 1, 0, 0, 0, 2, 1, 1, 0, 1, 0, 0, 0, 1, 0, 0, 0, 0, 0, 0, 0, 1, 1, 2, 1, 2, 1, 1, 0, 2, 1, 1, 0, 1, 0, 0, 0, 2, 1, 1, 0, 1, 0, 0, 0, 1, 0, 0, 0, 0, 0, 0, 0, 2, 1, 1, 0, 1, 0, 0, 0, 1 (list; graph; listen)

	OFFSET	`0,7`
	COMMENT	`The powers do not need to be distinct.`
	FORMULA	`For n>2: a(n) = (1 + (1 - A000120(n) mod 2)(1 - n mod 2)) 0^floor(A000120(n)/4). - Reinhard Zumkeller (reinhard.zumkeller(AT)gmail.com), Dec 14 2003`
	MAPLE	`f := proc(n, k) option remember; if k > n then RETURN(0); fi; if k= 0 then if n=0 then RETURN(1) else RETURN(0); fi; fi; if n mod 2 = 1 then RETURN(f(n-1, k-1)); fi; f(n-1, k-1)+f(n/2, k); end; # present sequence is f(n, 3)`
	CROSSREFS	`A column of A089052. Cf. A036987, A075897, A089049, A089050, A089051, A089053.` `Sequence in context: A154844 A133831 A066955 this_sequence A133162 A079806 A045887` `Adjacent sequences: A089045 A089046 A089047 this_sequence A089049 A089050 A089051`
	KEYWORD	`nonn`
	AUTHOR	`N. J. A. Sloane (njas(AT)research.att.com), Dec 03 2003`

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Last modified November 25 20:09 EST 2009. Contains 167514 sequences.

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