cp's OEIS Frontend

This is a front-end for the Online Encyclopedia of Integer Sequences, made by Christian Perfect. The idea is to provide OEIS entries in non-ancient HTML, and then to think about how they're presented visually. The source code is on GitHub.

A102412 Odd triangle !n. This table read by rows gives the coefficients of sum formulas of n-th Left factorials (A003422). The k-th row (6>=k>=1) contains T(i,k) for i=1 to k+1, where k=[2*n+3+(-1)^n]/4 and T(i,k) satisfies !n = Sum_{i=1..k+1} T(i,k) * n^(i-1) / (2*k-2)!.

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%I A102412 #15 Jun 16 2016 23:27:27
%S A102412 0,1,-4,4,0,96,-396,108,0,1012320,-192900,-64890,11460,90,-2038014720,
%T A102412 1977810240,-304486560,-12131280,2792160,21840,-33190735737600,
%U A102412 4445760574080,2334485260800,-394554283200,2330344800,1198048320,8215200
%N A102412 Odd triangle !n. This table read by rows gives the coefficients of sum formulas of n-th Left factorials (A003422). The k-th row (6>=k>=1) contains T(i,k) for i=1 to k+1, where k=[2*n+3+(-1)^n]/4 and T(i,k) satisfies !n = Sum_{i=1..k+1} T(i,k) * n^(i-1) / (2*k-2)!.
%C A102412 Incidentally, the sum of signed coefficients for each k-th row is divisible by (2*k-2)!.
%e A102412 Triangle starts:
%e A102412 0, 1;
%e A102412 -4, 4, 0;
%e A102412 96, -396, 108, 0;
%e A102412 1012320, -192900, -64890, 11460, 90;
%e A102412 -2038014720, 1977810240, -304486560, -12131280, 2792160, 21840;
%e A102412 ...
%e A102412 !11=4037914; substituting n=11 in the formula of the k-th row we obtain k=6 and the coefficients T(i,6) are those needed for computing !11.
%e A102412 => !11 = [ -33190735737600 +4445760574080*11 +2334485260800*11^2 -394554283200*11^3 +2330344800*11^4 +1198048320*11^5 +8215200*11^6 ]/10! = 4037914.
%Y A102412 Cf. A102411, A094638, A094216, A003422, A008276, A101752, A102409, A102410, A101751, A000142, A101559, A101032, A099731.
%K A102412 sign,tabf,uned
%O A102412 1,3
%A A102412 _André F. Labossière_, Jan 07 2005