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 A135889 Column 0 of triangle A135888, which equals the matrix cube of triangle A135880; also equals column 1 of triangle A135894. 3
 1, 3, 12, 63, 421, 3472, 34380, 399463, 5344770, 81097517, 1377986373, 25947738574, 536726987593, 12104879913657, 295754724799758, 7784814503249896, 219682110287448760, 6617691928179590112 (list; graph; refs; listen; history; text; internal format)
 OFFSET 0,2 LINKS Table of n, a(n) for n=0..17. PROG (PARI) {a(n)=local(P=Mat(1), R, PShR); if(n==0, 1, for(i=0, n, 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^3)[n+1, 1])} CROSSREFS Cf. A135888, A135890; A135880, A135894. Sequence in context: A373770 A238887 A351778 * A369746 A124562 A172450 Adjacent sequences: A135886 A135887 A135888 * A135890 A135891 A135892 KEYWORD nonn AUTHOR Paul D. Hanna, Dec 15 2007 STATUS approved

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Last modified August 4 01:12 EDT 2024. Contains 374905 sequences. (Running on oeis4.)