id:A108490 - OEIS Search Results

Search: id:A108490

Displaying 1-1 of 1 results found.

page 1

Expansion of 1/sqrt(1-4x-8x^2-24x^3+36x^4).

+0
1

1, 2, 10, 56, 268, 1448, 7864, 42752, 236368, 1313696, 7339552, 41217920, 232321984, 1313731712, 7449834880, 42347380736, 241225384192, 1376662561280, 7869527190016, 45051709749248, 258256281078784, 1482218578159616 (list; graph; listen)

	OFFSET	`0,2`
	COMMENT	`In general, sum{k=0..n, C(n-k,k)^2a^kb^(n-k)} has expansion 1/sqrt(1-2bx-(2ab-b^2)x^2-2ab^2x^3+(ab)^2*x^4).`
	FORMULA	`a(n)=sum{k=0..n, C(n-k, k)^23^k2^(n-k)}.`
	CROSSREFS	`Cf. A108486.` `Sequence in context: A009322 A102536 A122826 this_sequence A000172 A097971 A093303` `Adjacent sequences: A108487 A108488 A108489 this_sequence A108491 A108492 A108493`
	KEYWORD	`easy,nonn`
	AUTHOR	`Paul Barry (pbarry(AT)wit.ie), Jun 04 2005`

page 1

Search completed in 0.002 seconds

Last modified September 6 00:03 EDT 2008. Contains 143485 sequences.

AT&T Labs Research