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 A135892 Triangle, read by rows, equal to P^5, where triangle P = A135880. 5
 1, 5, 1, 30, 10, 1, 220, 95, 15, 1, 1945, 990, 195, 20, 1, 20340, 11635, 2625, 330, 25, 1, 247066, 154450, 38270, 5440, 500, 30, 1, 3430936, 2302142, 611525, 94515, 9750, 705, 35, 1, 53741404, 38229214, 10721093, 1761940, 196500, 15870, 945, 40, 1 (list; table; graph; refs; listen; history; text; internal format)
 OFFSET 0,2 COMMENTS Triangle P = A135880 is defined by: 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. LINKS Table of n, a(n) for n=0..44. FORMULA Column k of P^5 = column 2 of R^(k+1) for k>=0 where triangle R = A135894; column 0 of P^5 = column 2 of R; column 1 of P^5 = column 2 of R^2; column 2 of P^5 = column 2 of R^3; column 3 of P^5 = column 2 of R^4. EXAMPLE Triangle P^5 begins: 1; 5, 1; 30, 10, 1; 220, 95, 15, 1; 1945, 990, 195, 20, 1; 20340, 11635, 2625, 330, 25, 1; 247066, 154450, 38270, 5440, 500, 30, 1; 3430936, 2302142, 611525, 94515, 9750, 705, 35, 1; 53741404, 38229214, 10721093, 1761940, 196500, 15870, 945, 40, 1; 938816814, 701685738, 205607124, 35429974, 4182295, 363820, 24115, 1220, 45, 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; ... in which column k of P = column 0 of R^(k+1), where R = A135894 begins: 1; 1, 1; 2, 3, 1; 6, 12, 5, 1; 25, 63, 30, 7, 1; 138, 421, 220, 56, 9, 1; 970, 3472, 1945, 525, 90, 11, 1; ... in which column k of R equals column 0 of P^(2k+1). 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^5)[n+1, k+1]} CROSSREFS Cf. A135880 (P), A135894 (R), A135895 (R^2), A135896 (R^3), A135897 (R^4). Sequence in context: A214882 A144890 A144891 * A049460 A145926 A062140 Adjacent sequences: A135889 A135890 A135891 * A135893 A135894 A135895 KEYWORD nonn,tabl AUTHOR Paul D. Hanna, Dec 15 2007 STATUS approved

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Last modified July 21 16:28 EDT 2024. Contains 374475 sequences. (Running on oeis4.)