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.

A209936 Triangle of multiplicities of k-th partition of n corresponding to sequence A080577. Multiplicity of a given partition of n into k parts is the number of ways parts can be selected from k distinguishable bins. See the example.

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%I A209936 #42 Jan 29 2025 12:12:52
%S A209936 1,2,1,3,6,1,4,12,6,12,1,5,20,20,30,30,20,1,6,30,30,60,15,120,60,20,
%T A209936 90,30,1,7,42,42,105,42,210,140,105,105,420,105,140,210,42,1,8,56,56,
%U A209936 168,56,336,280,28,336,168,840,280,168,420,840,1120,168,70,560,420,56,1
%N A209936 Triangle of multiplicities of k-th partition of n corresponding to sequence A080577. Multiplicity of a given partition of n into k parts is the number of ways parts can be selected from k distinguishable bins. See the example.
%C A209936 Differs from A035206 after position 21.
%C A209936 Differs from A210238 after position 21.
%C A209936 The n-th row of the triangle, written as a column vector v(n), satisfies  K . v(n) = #SSYT(lambda,n) where K is the Kostka matrix of order n, and #SSYT(lambda,n) is the count of semi-standard Young tableaux in n variables of the partitions of n. - _Wouter Meeussen_, Jan 27 2025
%H A209936 Sergei Viznyuk, <a href="http://phystech.com/ftp/s_A209936.c">C Program</a>
%e A209936 Triangle begins:
%e A209936   1
%e A209936   2, 1
%e A209936   3, 6, 1
%e A209936   4, 12, 6, 12, 1
%e A209936   5, 20, 20, 30, 30, 20, 1
%e A209936   6, 30, 30, 60, 15, 120, 60, 20, 90, 30, 1
%e A209936   7, 42, 42, 105, 42, 210, 140, 105, 105, 420, 105, 140, 210, 42, 1
%e A209936   ...
%e A209936 Thus for n=3 (third row) the partitions of n=3 are:
%e A209936   3+0+0  0+3+0  0+0+3   (multiplicity=3),
%e A209936   2+1+0  2+0+1  1+2+0  1+0+2  0+2+1  0+1+2  (multiplicity=6),
%e A209936   1+1+1  (multiplicity=1).
%t A209936 Apply[Multinomial,Last/@Tally[#]&/@PadRight[IntegerPartitions[n]],1] (* _Wouter Meeussen_, Jan 26 2025 *)
%Y A209936 Cf. A080577, A078760, A035206, A210238.
%Y A209936 Row lengths give A000041.
%Y A209936 Row sums give A088218.
%K A209936 nonn,tabf
%O A209936 1,2
%A A209936 _Sergei Viznyuk_, Mar 15 2012