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A185623
Column 3 of triangular matrix T = A185620, which satisfies: T^3 - T^2 + I = SHIFT_LEFT(T).
3
1, 1, 7, 52, 442, 4345, 49114, 632104, 9167575, 148388893, 2657338636, 52244218837, 1120000171417, 26024217218746, 651943279016898, 17525338687574976, 503409841260165202, 15393623230236299133
OFFSET
0,3
PROG
(PARI) {A185620(n, k)=local(A=Mat(1), B); for(m=1, n, B=A^3-A^2+A^0;
A=matrix(m+1, m+1); for(i=1, m+1, for(j=1, i, if(i<2|j==i, A[i, j]=1,
if(j==1, A[i, j]=1, A[i, j]=B[i-1, j-1]))))); return(A[n+1, k+1])}
/* Column 3: */ {a(n)=A185620(n+3, 3)}
CROSSREFS
KEYWORD
nonn
AUTHOR
Paul D. Hanna, Feb 01 2011
STATUS
approved