|
Search: id:A135887
|
|
| |
|
| 1, 6, 42, 351, 3470, 39968, 528306, 7906598, 132426050, 2457643895, 50110693656, 1114365815786, 26856942480503, 697612318151050, 19435260247394150, 578255661792065917, 18303904706366202568, 614296560055922433760
(list; graph; listen)
|
|
|
OFFSET
|
0,2
|
|
|
EXAMPLE
|
Triangle Q = A135885 begins:
1;
2, 1;
6, 4, 1;
25, 20, 6, 1;
138, 126, 42, 8, 1;
970, 980, 351, 72, 10, 1;
8390, 9186, 3470, 748, 110, 12, 1; ...
where column k of Q equals column 0 of Q^(k+1) such that
column 0 of Q equals column 0 of P=A135880 shift left and Q=P^2.
|
|
PROGRAM
|
(PARI) {a(n)=local(P=Mat(1), R, PShR); if(n==0, 1, for(i=0, n+1, PShR=matrix(#P, #P, r, c, if(r>=c, if(r==c, 1, if(c==1, 0, P[r-1, c-1])))); R=P*PShR; R=matrix(#P+1, #P+1, r, c, if(r>=c, if(r<#P+1, R[r, c], if(c==1, (P^2)[ #P, 1], (P^(2*c-1))[r-c+1, 1])))); P=matrix(#R, #R, r, c, if(r>=c, if(r<#R, P[r, c], (R^c)[r-c+1, 1])))); (P^2)[n+3, 3])}
|
|
CROSSREFS
|
Cf. A135885 (Q), A135893 (Q^3), A135880; other columns: A135881, A135886.
Sequence in context: A123510 A132804 A074017 this_sequence A052589 A074107 A052608
Adjacent sequences: A135884 A135885 A135886 this_sequence A135888 A135889 A135890
|
|
KEYWORD
|
nonn
|
|
AUTHOR
|
Paul D. Hanna (pauldhanna(AT)juno.com), Dec 15 2007
|
|
|
Search completed in 0.002 seconds
|
