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Search: id:A121421
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A121421 Column 0 of triangle A121420. +0
6
1, 3, 12, 76, 711, 9054, 147471, 2938176, 69328365, 1891371807, 58575539361, 2030011517685, 77827890696820, 3270046577551695, 149407542447596319, 7374639622066056408, 391044078030333899385, 22168014954558449549349 (list; graph; listen)
OFFSET

0,2

COMMENT

A121420 is the matrix cube of triangle A121412; row n of triangle T=A121412 equals row (n-1) of T^(n+1) with an appended '1'.

PROGRAM

(PARI) {a(n)=local(A=Mat(1), B); for(m=1, n+1, B=matrix(m, m); for(i=1, m, for(j=1, i, if(j==i, B[i, j]=1, B[i, j]=(A^i)[i-1, j]); )); A=B); return((A^3)[n+1, 1])}

CROSSREFS

Cf. A121420 (triangle); other columns: A121422, A121423.

Sequence in context: A120591 A032114 A060946 this_sequence A136735 A108043 A058561

Adjacent sequences: A121418 A121419 A121420 this_sequence A121422 A121423 A121424

KEYWORD

nonn

AUTHOR

Paul D. Hanna (pauldhanna(AT)juno.com), Aug 23 2006

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Last modified September 6 09:40 EDT 2008. Contains 143480 sequences.


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