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A172427 Triangle T(n, k, q) = c(n,q)/( c(k,q)*c(n-k,q) ), where c(n, q) = Product_{j=1..n} f(n, q), f(n, q) = ( (1-q^n)*(1+(-1)^n) + n!*(1-(-1)^n) )/2, and q = 2, read by rows. 3

%I #8 May 08 2021 01:41:15

%S 1,1,1,1,-3,1,1,6,6,1,1,-15,30,-15,1,1,120,600,600,120,1,1,-63,2520,

%T -6300,2520,-63,1,1,5040,105840,2116800,2116800,105840,5040,1,1,-255,

%U 428400,-4498200,35985600,-4498200,428400,-255,1,1,362880,30844800,25909632000,108820454400,108820454400,25909632000,30844800,362880,1

%N Triangle T(n, k, q) = c(n,q)/( c(k,q)*c(n-k,q) ), where c(n, q) = Product_{j=1..n} f(n, q), f(n, q) = ( (1-q^n)*(1+(-1)^n) + n!*(1-(-1)^n) )/2, and q = 2, read by rows.

%H G. C. Greubel, <a href="/A172427/b172427.txt">Rows n = 0..30 of the triangle, flattened</a>

%F T(n, k, q) = c(n,q)/( c(k,q)*c(n-k,q) ), where c(n, q) = Product_{j=1..n} f(n, q), f(n, q) = ( (1-q^n)*(1+(-1)^n) + n!*(1-(-1)^n) )/2, and q = 2.

%e Triangle begins as:

%e 1;

%e 1, 1;

%e 1, -3, 1;

%e 1, 6, 6, 1;

%e 1, -15, 30, -15, 1;

%e 1, 120, 600, 600, 120, 1;

%e 1, -63, 2520, -6300, 2520, -63, 1;

%e 1, 5040, 105840, 2116800, 2116800, 105840, 5040, 1;

%e 1, -255, 428400, -4498200, 35985600, -4498200, 428400, -255, 1;

%t f[n_, q_]:= ((1-q^n)*(1+(-1)^n) + n!*(1-(-1)^n))/2;

%t c[n_, q_]:= Product[f[j, q], {j, n}];

%t T[n_, k_, q_]:= c[n, q]/(c[k, q]*c[n-k, q]);

%t Table[T[n, k, 2], {n,0,12}, {k,0,n}]//Flatten (* modified by _G. C. Greubel_, May 07 2021 *)

%o (Sage)

%o @CachedFunction

%o def f(n,q): return ((1-q^n)*(1+(-1)^n) + factorial(n)*(1-(-1)^n))/2

%o def c(n,q): return product( f(j,q) for j in (1..n) )

%o def T(n,k,q): return c(n,q)/(c(k,q)*c(n-k,q))

%o flatten([[T(n,k,2) for k in (0..n)] for n in (0..12)]) # _G. C. Greubel_, May 07 2021

%Y Cf. this sequence (q=3), A172428 (q=4), A172429 (q=5).

%K sign,tabl

%O 0,5

%A _Roger L. Bagula_, Feb 02 2010

%E Edited by _G. C. Greubel_, May 07 2021

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Last modified July 28 04:17 EDT 2024. Contains 374674 sequences. (Running on oeis4.)