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 A136233 Matrix square of triangle U = A136228, read by rows. 2
 1, 2, 1, 10, 8, 1, 75, 76, 14, 1, 753, 888, 196, 20, 1, 9534, 12542, 3087, 370, 26, 1, 146353, 209506, 55552, 7320, 598, 32, 1, 2647628, 4058806, 1136975, 159645, 14235, 880, 38, 1, 55251994, 89706276, 26224597, 3856065, 364403, 24480, 1216, 44, 1 (list; table; graph; refs; listen; history; text; internal format)
 OFFSET 0,2 LINKS Table of n, a(n) for n=0..44. FORMULA Column k of U^2 (this triangle) = column 1 of P^(3k+1), where P = triangle A136220. EXAMPLE This triangle, U^2, begins: 1; 2, 1; 10, 8, 1; 75, 76, 14, 1; 753, 888, 196, 20, 1; 9534, 12542, 3087, 370, 26, 1; 146353, 209506, 55552, 7320, 598, 32, 1; 2647628, 4058806, 1136975, 159645, 14235, 880, 38, 1; 55251994, 89706276, 26224597, 3856065, 364403, 24480, 1216, 44, 1; ... where column 0 of U^2 = column 1 of P = A136220. PROG (PARI) {T(n, k)=local(P=Mat(1), U=Mat(1), 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])))); U=P*PShR^2; U=matrix(#P+1, #P+1, r, c, if(r>=c, if(r<#P+1, U[r, c], if(c==1, (P^3)[ #P, 1], (P^(3*c-1))[r-c+1, 1])))); P=matrix(#U, #U, r, c, if(r>=c, if(r<#R, P[r, c], (U^c)[r-c+1, 1]))))); (U^2)[n+1, k+1]} CROSSREFS Cf. A136222 (column 0); related tables: A136220 (P), A136228 (U), A136230 (V), A136231 (W=P^3), A136236 (U^3). Sequence in context: A213252 A122017 A219900 * A113088 A060694 A217108 Adjacent sequences: A136230 A136231 A136232 * A136234 A136235 A136236 KEYWORD nonn,tabl AUTHOR Paul D. Hanna, Feb 07 2008 STATUS approved

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Last modified December 5 02:53 EST 2023. Contains 367567 sequences. (Running on oeis4.)