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 A135888 Triangle, read by rows, equal to the matrix cube of triangle P = A135880. 7
 1, 3, 1, 12, 6, 1, 63, 39, 9, 1, 421, 300, 81, 12, 1, 3472, 2741, 816, 138, 15, 1, 34380, 29380, 9366, 1716, 210, 18, 1, 399463, 363922, 122148, 23647, 3105, 297, 21, 1, 5344770, 5135894, 1795481, 362116, 49880, 5088, 399, 24, 1, 81097517, 81557270 (list; table; graph; refs; listen; history; text; internal format)
 OFFSET 0,2 COMMENTS Matrix square equals triangle A135893. LINKS EXAMPLE Triangle P^3 begins: 1; 3, 1; 12, 6, 1; 63, 39, 9, 1; 421, 300, 81, 12, 1; 3472, 2741, 816, 138, 15, 1; 34380, 29380, 9366, 1716, 210, 18, 1; 399463, 363922, 122148, 23647, 3105, 297, 21, 1; 5344770, 5135894, 1795481, 362116, 49880, 5088, 399, 24, 1; 81097517, 81557270, 29478724, 6138746, 875935, 93306, 7770, 516, 27, 1; where P = A135880 begins: 1; 1, 1; 2, 2, 1; 6, 7, 3, 1; 25, 34, 15, 4, 1; 138, 215, 99, 26, 5, 1; 970, 1698, 814, 216, 40, 6, 1; ... where column k of P^2 equals column 0 of P^(2k+2) such that column 0 of P^2 equals column 0 of P shift left. PROG (PARI) {T(n, k)=local(P=Mat(1), R, PShR); if(n>0, 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, k+1]} CROSSREFS Cf. columns: A135889, A135890; related tables: A135880 (P), A135894 (R), A135893 (P^6). Sequence in context: A127894 A127898 A078938 * A329433 A258245 A133366 Adjacent sequences:  A135885 A135886 A135887 * A135889 A135890 A135891 KEYWORD nonn,tabl AUTHOR Paul D. Hanna, Dec 15 2007 STATUS approved

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Last modified June 15 18:33 EDT 2021. Contains 345049 sequences. (Running on oeis4.)