A185623 Column 3 of triangular matrix T = A185620, which satisfies: T^3 - T^2 + I = SHIFT_LEFT(T).

1, 1, 7, 52, 442, 4345, 49114, 632104, 9167575, 148388893, 2657338636, 52244218837, 1120000171417, 26024217218746, 651943279016898, 17525338687574976, 503409841260165202, 15393623230236299133

Offset

0,3

Links

Table of n, a(n) for n=0..17.

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

Cf. A185620, A185621, A185622.

Sequence in context: A349532 A369147 A162233 * A193881 A249349 A300492

Adjacent sequences: A185620 A185621 A185622 * A185624 A185625 A185626

Keyword

nonn

Author

Paul D. Hanna, Feb 01 2011

Status

approved