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.

A333310 Triangle read by rows: T(n,k) is the number of permutations sigma of [n] such that sigma(1) = k and sigma(j)/j > sigma(j+1)/(j+1) for 1 <= j <= n-1.

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%I A333310 #17 Mar 15 2020 02:48:45
%S A333310 1,0,1,0,1,1,0,1,1,1,0,1,2,1,2,0,1,2,2,1,3,0,1,3,5,2,3,5,0,1,3,6,5,3,
%T A333310 4,8,0,1,4,8,12,8,5,9,13,0,1,4,12,20,18,8,11,13,21,0,1,5,18,29,42,21,
%U A333310 22,19,27,38,0,1,5,23,44,69,48,33,30,33,38,64
%N A333310 Triangle read by rows: T(n,k) is the number of permutations sigma of [n] such that sigma(1) = k and sigma(j)/j > sigma(j+1)/(j+1) for 1 <= j <= n-1.
%C A333310 T(n+1,k+1) is equal to the number of permutations sigma of [n] such that sigma(1) = k and sigma(j)/j >= sigma(j+1)/(j+1) for 1 <= j <= n-1.
%H A333310 Seiichi Manyama, <a href="/A333310/b333310.txt">Rows n = 1..18, flattened</a>
%H A333310 Mathematics.StackExchange, <a href="https://math.stackexchange.com/questions/3572301/why-are-the-numbers-of-two-different-permutations-the-same">Why are the numbers of two different permutations the same?</a>, Mar 07 2020.
%e A333310 Triangle begins:
%e A333310 n\k  | 1  2  3   4   5   6   7   8   9  10  11  12
%e A333310 -----+--------------------------------------------
%e A333310    1 | 1;
%e A333310    2 | 0, 1;
%e A333310    3 | 0, 1, 1;
%e A333310    4 | 0, 1, 1,  1;
%e A333310    5 | 0, 1, 2,  1,  2;
%e A333310    6 | 0, 1, 2,  2,  1,  3;
%e A333310    7 | 0, 1, 3,  5,  2,  3,  5;
%e A333310    8 | 0, 1, 3,  6,  5,  3,  4,  8;
%e A333310    9 | 0, 1, 4,  8, 12,  8,  5,  9, 13;
%e A333310   10 | 0, 1, 4, 12, 20, 18,  8, 11, 13, 21;
%e A333310   11 | 0, 1, 5, 18, 29, 42, 21, 22, 19, 27, 38;
%e A333310   12 | 0, 1, 5, 23, 44, 69, 48, 33, 30, 33, 38, 64;
%Y A333310 Row sums give A309807.
%Y A333310 Cf. A332954.
%K A333310 nonn,tabl
%O A333310 1,13
%A A333310 _Seiichi Manyama_, Mar 14 2020