id:A072931 - OEIS Search Results

Search: id:A072931

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Number of ways to write n as a sum of 2 semiprimes.

+0
3

0, 0, 0, 0, 0, 0, 0, 1, 0, 1, 0, 1, 1, 1, 1, 1, 0, 2, 2, 2, 1, 0, 1, 2, 2, 1, 1, 2, 2, 3, 3, 2, 0, 1, 3, 3, 2, 1, 3, 3, 2, 3, 4, 4, 2, 1, 4, 5, 3, 3, 1, 3, 3, 2, 5, 3, 2, 2, 5, 6, 6, 1, 3, 5, 3, 4, 4, 5, 3, 3, 6, 7, 5, 3, 3, 4, 4, 4, 5, 5, 3, 2, 7, 7, 2, 4, 4, 5, 4, 6, 8, 6, 3, 3, 8, 7, 7, 4, 6, 8, 6, 5, 7, 7, 2 (list; graph; listen)

	OFFSET	`1,18`
	COMMENT	`Sequence is probably >0 for n> 33.` `The graph of this sequence is compelling evidence that 33 is the last term of sequence A072966. - T. D. Noe, Apr 10 2007`
	LINKS	`T. D. Noe, Table of n, a(n) for n=1..10000`
	PROGRAM	`(PARI) a(n)=sum(i=1, n, sum(j=1, i, if(abs(bigomega(i)-2)+abs(bigomega(j)-2)+abs(n-i-j), 0, 1)))`
	CROSSREFS	`Cf. A001358, A072966.` `Sequence in context: A124747 A039981 A006140 this_sequence A112211 A112215 A076451` `Adjacent sequences: A072928 A072929 A072930 this_sequence A072932 A072933 A072934`
	KEYWORD	`easy,nonn`
	AUTHOR	`Benoit Cloitre (benoit7848c(AT)orange.fr), Aug 13 2002`

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Last modified December 16 17:18 EST 2009. Contains 170825 sequences.

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