A102227 - OEIS

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A102227

Column 1 of triangular matrix A102225, in which row k is formed from the first differences of row (k-1) of its matrix square (A102228).

0, 1, -1, -5, -20, -51, -289, -1426, -22622, -259734, -15968025, -405699154, -110016092396, -6660687936224, -7918107904514781, -1332064204800175993, -6282110941080800842150, -3412055538464918268114551, -57520868453379641772222723912

(list; graph; refs; listen; history; text; internal format)

OFFSET

0,4

LINKS

Table of n, a(n) for n=0..18.

FORMULA

a(n) = A102229(n-1) - A102226(n) for n>=2, where A102226 equals column 0 of A102225 and A102229 equals column 1 of A102228.

PROG

(PARI) {a(n)=local(A=matrix(2, 2), B); A[1, 1]=1; for(m=2, n+1, B=matrix(m, m); for(i=1, m, for(j=1, i, if(j==i, B[i, j]=1, if(j==1, B[i, j]=(A^2)[i-1, 1], B[i, j]=(A^2)[i-1, j]-(A^2)[i-1, j-1])); )); A=B); return(A[n+1, 2])}

CROSSREFS

Cf. A102225, A102226, A102228, A102229.

Sequence in context: A034133 A006504 A007045 * A173034 A006010 A270334

Adjacent sequences: A102224 A102225 A102226 * A102228 A102229 A102230

KEYWORD

sign

AUTHOR

Paul D. Hanna, Jan 01 2005

STATUS

approved