A115638 - OEIS

This site is supported by donations to The OEIS Foundation.

A115638

A Jacobsthal-related divide-and-conquer sequence.

1, -1, 5, -1, -3, -1, 21, -1, -3, -1, -11, -1, -3, -1, 85, -1, -3, -1, -11, -1, -3, -1, -43, -1, -3, -1, -11, -1, -3, -1, 341, -1, -3, -1, -11, -1, -3, -1, -43, -1, -3, -1, -11, -1, -3, -1, -171, -1, -3, -1, -11, -1, -3, -1, -43, -1, -3, -1, -11, -1, -3, -1, 1365, -1, -3, -1, -11, -1, -3, -1, -43 (list; graph; refs; listen; history; internal format)

	OFFSET	`0,3`
	COMMENTS	`Partial sums are A115637.`
	LINKS	`R. Stephan, Divide-and-conquer generating functions. I. Elementary sequences`
	FORMULA	`G.f.: sum{k>=0, 4^kx^(2^(k+1)-2)/(1+x^(2^k))}; The g.f. G(x) satisfies G(x)-4x^2G(x^2)=1/(1+x).`
	CROSSREFS	`Cf. A001045.` `Sequence in context: A111740 A155059 A206076 * A055515 A136744 A068237` `Adjacent sequences: A115635 A115636 A115637 * A115639 A115640 A115641`
	KEYWORD	`easy,sign`
	AUTHOR	`Paul Barry (pbarry(AT)wit.ie), Jan 27 2006`

Content is available under The OEIS End-User License Agreement .

Last modified February 17 04:52 EST 2012. Contains 205985 sequences.