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.

A322596 Square array read by descending antidiagonals (n >= 0, k >= 0): let b(n,k) = (n+k)!/((n+1)!*k!); then T(n,k) = b(n,k) if b(n,k) is an integer, and T(n,k) = floor(b(n,k)) + 1 otherwise.

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%I A322596 #10 Feb 15 2021 03:44:44
%S A322596 1,1,1,1,1,1,1,2,1,1,1,2,2,1,1,1,3,4,3,1,1,1,3,5,5,3,1,1,1,4,7,9,7,4,
%T A322596 1,1,1,4,10,14,14,10,4,1,1,1,5,12,21,26,21,12,5,1,1,1,5,15,30,42,42,
%U A322596 30,15,5,1,1,1,6,19,42,66,77,66,42,19,6,1,1,1,6,22,55,99,132,132,99,55,22,6,1,1
%N A322596 Square array read by descending antidiagonals (n >= 0, k >= 0): let b(n,k) = (n+k)!/((n+1)!*k!); then T(n,k) = b(n,k) if b(n,k) is an integer, and T(n,k) = floor(b(n,k)) + 1 otherwise.
%C A322596 For n >= 1, T(n,k) is the number of nodes in n-dimensional space for Mysovskikh's cubature formula which is exact for any polynomial of degree k of n variables.
%H A322596 Ronald Cools, <a href="http://nines.cs.kuleuven.be/ecf/">Encyclopaedia of Cubature Formulas</a>
%H A322596 Ivan P. Mysovskikh, <a href="https://doi.org/10.1016/0041-5553(64)90212-5">On the construction of cubature formulae for very simple domains</a>, USSR Computational Mathematics and Mathematical Physics, Volume 4, Issue 1, 1964, 1-17.
%e A322596 Array begins:
%e A322596   1, 1, 1,  1,  1,   1,   1,    1,    1,    1, ...
%e A322596   1, 1, 2,  2,  3,   3,   4,    4,    5,    5, ...
%e A322596   1, 1, 2,  4,  5,   7,  10,   12,   15,   19, ...
%e A322596   1, 1, 3,  5,  9,  14,  21,   30,   42,   55, ...
%e A322596   1, 1, 3,  7, 14,  26,  42,   66,   99,  143, ...
%e A322596   1, 1, 4, 10, 21,  42,  77,  132,  215,  334, ...
%e A322596   1, 1, 4, 12, 30,  66, 132,  246,  429,  715, ...
%e A322596   1, 1, 5, 15, 42,  99, 215,  429,  805, 1430, ...
%e A322596   1, 1, 5, 19, 55, 143, 334,  715, 1430, 2702, ...
%e A322596   1, 1, 6, 22, 72, 201, 501, 1144, 2431, 4862, ...
%e A322596   ...
%e A322596 As triangular array, this begins:
%e A322596   1;
%e A322596   1, 1;
%e A322596   1, 1,  1;
%e A322596   1, 2,  1,  1;
%e A322596   1, 2,  2,  1,  1;
%e A322596   1, 3,  4,  3,  1,  1;
%e A322596   1, 3,  5,  5,  3,  1,  1;
%e A322596   1, 4,  7,  9,  7,  4,  1,  1;
%e A322596   1, 4, 10, 14, 14, 10,  4,  1, 1;
%e A322596   1, 5, 12, 21, 26, 21, 12,  5, 1, 1;
%e A322596   1, 5, 15, 30, 42, 42, 30, 15, 5, 1, 1;
%e A322596   ...
%o A322596 (Maxima)
%o A322596 b(n, k) := (n + k)!/((n + 1)!*k!)$
%o A322596 T(n, k) := if integerp(b(n, k)) then b(n, k) else floor(b(n, k)) + 1$
%o A322596 create_list(T(k, n - k), n, 0, 15, k, 0, n);
%Y A322596 Main diagonal: A000108.
%Y A322596 Cf. A007318, A037306, A046854, A047996, A065941, A241926, A267632.
%K A322596 nonn,easy,tabl
%O A322596 0,8
%A A322596 _Franck Maminirina Ramaharo_, Jan 22 2019