id:A007415 - OEIS Search Results

Search: id:A007415

Displaying 1-1 of 1 results found.

page 1

Expand sin x / exp x = x-x^2+x^3/3-x^5/30+... and invert nonzero coefficients.

+0
6

0, 1, -1, 3, 0, -30, 90, -630, 0, 22680, -113400, 1247400, 0, -97297200, 681080400, -10216206000, 0, 1389404016000, -12504636144000, 237588086736000, 0, -49893498214560000, 548828480360160000, -12623055048283680000 (list; graph; listen)

	OFFSET	`0,4`
	FORMULA	`a(n) = [n mod 4 > 0] * (-1)^(n+1+[n/4]) * n!/2^[n/2]. - Ralf Stephan (ralf(AT)ark.in-berlin.de), Mar 06 2004`
	CROSSREFS	`Absolute values are essentially the same as A046979, where zeros are replaced by ones.` `a(4n+2) = -(-1)^nA052277(n), a(2n+1) = (-1)^[n/2]A007019(n).` `Cf. A046981, A007452, A009775, A092820.` `Adjacent sequences: A007412 A007413 A007414 this_sequence A007416 A007417 A007418` `Sequence in context: A057379 A009777 A138543 this_sequence A058833 A012775 A105751`
	KEYWORD	`sign`
	AUTHOR	`njas`

page 1

Search completed in 0.002 seconds

Last modified May 16 01:24 EDT 2008. Contains 139630 sequences.

AT&T Labs Research