A167432 - OEIS

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A167432

Riordan array (c(2x)^2,xc(2x)), c(x) the g.f. of A000108.

1, 4, 1, 20, 6, 1, 112, 36, 8, 1, 672, 224, 56, 10, 1, 4224, 1440, 384, 80, 12, 1, 27456, 9504, 2640, 600, 108, 14, 1, 183040, 64064, 18304, 4400, 880, 140, 16, 1, 1244672, 439296, 128128, 32032, 6864, 1232, 176, 18, 1, 8599552, 3055104, 905216, 232960 (list; table; graph; refs; listen; history; text; internal format)

	OFFSET	`0,2`
	COMMENTS	`Inverse of (1-4x+4x^2,x(1-2x)) (A167431). Row sums are A084076. First column is A003645.`
	LINKS	`Table of n, a(n) for n=0..48.`
	FORMULA	`Number triangle T(n,k)=A054445(n,k)*2^(n-k).`
	EXAMPLE	`Triangle begins` `1,` `4, 1,` `20, 6, 1,` `112, 36, 8, 1,` `672, 224, 56, 10, 1,` `4224, 1440, 384, 80, 12, 1,` `27456, 9504, 2640, 600, 108, 14, 1,` `183040, 64064, 18304, 4400, 880, 140, 16, 1,` `1244672, 439296, 128128, 32032, 6864, 1232, 176, 18, 1,` `8599552, 3055104, 905216, 232960, 52416, 10192, 1664, 216, 20, 1,` `60196864, 21498880, 6449664, 1697280, 396032, 81536, 14560, 2184, 260, 22, 1` `The production matrix is` `4, 1,` `4, 2, 1,` `8, 4, 2, 1,` `16, 8, 4, 2, 1,` `32, 16, 8, 4, 2, 1,` `64, 32, 16, 8, 4, 2, 1,` `128, 64, 32, 16, 8, 4, 2, 1,` `256, 128, 64, 32, 16, 8, 4, 2, 1,` `512, 256, 128, 64, 32, 16, 8, 4, 2, 1` `When topped with the row (1,0,0,0...), this has inverse` `1,` `-4, 1,` `4, -2, 1,` `0, 0, -2, 1,` `0, 0, 0, -2, 1,` `0, 0, 0, 0, -2, 1,` `0, 0, 0, 0, 0, -2, 1,` `0, 0, 0, 0, 0, 0, -2, 1,` `0, 0, 0, 0, 0, 0, 0, -2, 1,` `0, 0, 0, 0, 0, 0, 0, 0, -2, 1`
	CROSSREFS	`Sequence in context: A144886 A117380 A185420 * A201639 A078939 A135891` `Adjacent sequences: A167429 A167430 A167431 * A167433 A167434 A167435`
	KEYWORD	`easy,nonn,tabl`
	AUTHOR	`Paul Barry, Nov 03 2009`
	STATUS	`approved`

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Last modified May 26 20:51 EDT 2022. Contains 354092 sequences. (Running on oeis4.)