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.

A357340 Triangle read by rows. T(n, k) = Sum_{j=0..n-k} binomial(-n, j) * A268438(n - k, j).

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%I A357340 #13 Dec 10 2023 09:23:38
%S A357340 1,-1,1,2,-2,1,0,12,-3,1,-56,-120,28,-4,1,0,1680,-450,50,-5,1,15840,
%T A357340 -30240,10416,-1080,78,-6,1,0,665280,-317520,33712,-2100,112,-7,1,
%U A357340 -17297280,-17297280,12070080,-1391040,81648,-3600,152,-8,1
%N A357340 Triangle read by rows. T(n, k) = Sum_{j=0..n-k} binomial(-n, j) * A268438(n - k, j).
%e A357340 Triangle T(n, k) starts:
%e A357340 [0]         1;
%e A357340 [1]        -1,         1;
%e A357340 [2]         2,        -2,        1;
%e A357340 [3]         0,        12,       -3,        1;
%e A357340 [4]       -56,      -120,       28,       -4,     1;
%e A357340 [5]         0,      1680,     -450,       50,    -5,     1;
%e A357340 [6]     15840,    -30240,    10416,    -1080,    78,    -6,   1;
%e A357340 [7]         0,    665280,  -317520,    33712, -2100,   112,  -7,  1;
%e A357340 [8] -17297280, -17297280, 12070080, -1391040, 81648, -3600, 152, -8, 1;
%p A357340 A357340 := proc(n, k) local u; u := n - k; (2*u)!*add(binomial(-n, j) * j! *
%p A357340   add((-1)^(j+m)*binomial(u+j, u+m)*abs(Stirling1(u+m, m)), m=0..j)/(u +j)!, j=0..u) end: seq(print(seq(A357340(n, k), k=0..n)), n=0..8);
%o A357340 (SageMath) # using function A268438
%o A357340 def A357340(n, k):
%o A357340     return sum(binomial(-n, i) * A268438(n - k, i) for i in range(n - k + 1))
%o A357340 for n in range(10): print([A357340(n, k) for k in range(n + 1)])
%Y A357340 Cf. A357341 (alternating row sums), A264437, A268438, A357339.
%K A357340 sign,tabl
%O A357340 0,4
%A A357340 _Peter Luschny_, Sep 25 2022