A113385 - OEIS

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A113385

Column 0 of triangle A113384.

1, 4, 22, 212, 3255, 70777, 2022897, 72375484, 3130502129, 159476810183, 9376968779265, 626244735454991, 46892450411406465, 3894861818247549265, 355651177699555693544, 35432761283736539730108 (list; graph; refs; listen; history; text; internal format)

	OFFSET	`0,2`
	LINKS	`Table of n, a(n) for n=0..15.`
	FORMULA	`A113384 equals the matrix square of A113381, which has the property: column k of A113381^2 = column 0 of A113381^(3*k+2) for k>=0.`
	PROG	`(PARI) a(n)=local(A, B); A=Mat(1); for(m=2, n+1, B=matrix(m, m); for(i=1, m, for(j=1, i, if(i<3 \|\| j==i \|\| j>m-1, B[i, j]=1, if(j==1, B[i, 1]=1, B[i, j]=(A^(3j-2))[i-j+1, 1])); )); A=B); (matrix(#A, #A, r, c, if(r>=c, (A^(3c-1))[r-c+1, 1]))^2)[n+1, 1]`
	CROSSREFS	`Cf. A113381, A113384, A113386 (column 1).` `Sequence in context: A103437 A215201 A063380 * A356285 A120482 A207156` `Adjacent sequences: A113382 A113383 A113384 * A113386 A113387 A113388`
	KEYWORD	`nonn`
	AUTHOR	`Paul D. Hanna, Nov 14 2005`
	STATUS	`approved`

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Last modified April 2 02:53 EDT 2023. Contains 361723 sequences. (Running on oeis4.)