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A255009 Array T(n,k) read by ascending antidiagonals, where T(n,k) is the denominator of polygamma(n, 1) - polygamma(n, k). 1

%I #10 Jan 05 2024 12:29:10

%S 1,1,1,1,1,2,1,1,4,6,1,1,4,36,12,1,1,8,108,144,60,1,1,4,216,864,3600,

%T 20,1,1,8,324,3456,108000,3600,140,1,1,8,1944,10368,2160000,12000,

%U 176400,280,1,1,16,1944,124416,32400000,2160000,4116000

%N Array T(n,k) read by ascending antidiagonals, where T(n,k) is the denominator of polygamma(n, 1) - polygamma(n, k).

%C See A255008.

%t T[n_, k_] := (-1)^(n+1)*n!*HarmonicNumber[k-1, n+1] // Denominator; Table[T[n-k, k], {n, 0, 10}, {k, 1, n}] // Flatten

%Y Cf. A001008, A002805, A007406, A007407, A255006, A255007, A255008 (numerators).

%K nonn,frac,tabl,easy

%O 0,6

%A _Jean-François Alcover_, Feb 12 2015

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