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.

A039754 Irregular triangle read by rows: T(n,k) = number of binary codes of length n with k words (n >= 0, 0 <= k <= 2^n); also number of 0/1-polytopes with vertices from the unit n-cube; also number of inequivalent Boolean functions of n variables with exactly k nonzero values under action of Jevons group.

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%I A039754 #60 Aug 28 2025 11:14:24
%S A039754 1,1,1,1,1,1,1,2,1,1,1,1,3,3,6,3,3,1,1,1,1,4,6,19,27,50,56,74,56,50,
%T A039754 27,19,6,4,1,1,1,1,5,10,47,131,472,1326,3779,9013,19963,38073,65664,
%U A039754 98804,133576,158658,169112,158658,133576,98804,65664,38073,19963,9013,3779,1326,472,131,47,10,5,1,1
%N A039754 Irregular triangle read by rows: T(n,k) = number of binary codes of length n with k words (n >= 0, 0 <= k <= 2^n); also number of 0/1-polytopes with vertices from the unit n-cube; also number of inequivalent Boolean functions of n variables with exactly k nonzero values under action of Jevons group.
%C A039754 For N=1 through N=5, the first 2^(N-1) terms of row N are also found in triangle A171871, which is related to A005646. This was shown for all N by _Andrew Weimholt_, Dec 30 2009. [_Robert Munafo_, Jan 25 2010]
%D A039754 F. Harary and E. M. Palmer, Graphical Enumeration, Academic Press, NY, 1973, p. 112.
%D A039754 M. A. Harrison, Introduction to Switching and Automata Theory. McGraw Hill, NY, 1965, p. 150.
%H A039754 Jan Brandts, A. Cihangir, <a href="http://arxiv.org/abs/1512.03044">Enumeration and investigation of acute 0/1-simplices modulo the action of the hyperoctahedral group</a>, arXiv preprint arXiv:1512.03044 [math.CO], 2015. See Fig. 13.
%H A039754 D. Condon, S. Coskey, L. Serafin, and C. Stockdale, <a href="http://arxiv.org/abs/1412.4683">On generalizations of separating and splitting families</a>, arXiv preprint arXiv:1412.4683 [math.CO], 2014-2015.
%H A039754 Jacob Feldman, <a href="https://ruccs.rutgers.edu/images/personal-jacob-feldman/papers/feldman_catalog.pdf">A catalog of Boolean concepts</a>, Journal of Mathematical Psychology, Volume 47, Issue 1, 2003, 75-89.
%H A039754 Harald Fripertinger, <a href="http://dx.doi.org/10.1023/A:1008248618779">Enumeration, construction and random generation of block codes</a>, Designs, Codes, Crypt., 14 (1998), 213-219.
%H A039754 Harald Fripertinger, <a href="http://www.mathe2.uni-bayreuth.de/frib/codes/tables.html">Isometry Classes of Codes</a>
%H A039754 Harald Fripertinger, <a href="http://www.mathe2.uni-bayreuth.de/frib/html2/construction/blockcodes_2.html">Enumeration of block codes</a>
%H A039754 Tilman Piesk, <a href="https://commons.wikimedia.org/wiki/File:Venn_and_Euler_diagrams_of_3-ary_Boolean_relations.svg">Illustration of row 3</a>
%H A039754 <a href="/index/Bo#Boolean">Index entries for sequences related to Boolean functions</a>
%F A039754 Reference gives g.f.
%F A039754 Fripertinger gives g.f. for the number of classes of (n, m) nonlinear codes over an alphabet of size A.
%e A039754 Triangle begins:
%e A039754   k  0  1  2  3   4   5   6   7   8   9  10  11  12 13 14 15 16   sums
%e A039754 n
%e A039754 0    1  1                                                            2
%e A039754 1    1  1  1                                                         3
%e A039754 2    1  1  2  1   1                                                  6
%e A039754 3    1  1  3  3   6   3   3   1   1                                 22
%e A039754 4    1  1  4  6  19  27  50  56  74  56  50  27  19  6  4  1  1    402
%t A039754 P = IntegerPartitions;
%t A039754 AC[d_Integer] := Module[{C, M, p},(* from W. Y. C. Chen algorithm *) M[p_List] := Plus @@ p!/(Times @@ p * Times @@ (Length /@ Split[p]!)); C[p_List, q_List] := Module[{r, m, k, x}, r = If[0 == Length[q], 1, 2*2^IntegerExponent[LCM @@ q, 2]]; m = LCM @@ Join[p/GCD[r, p], q/GCD[r, q]]; CoefficientList[Expand[Product[(1 + x^(k *r))^((Plus @@ Map[MoebiusMu[k/#]*2^Plus @@ GCD[#*r, Join[p, q]]&, Divisors[k]])/(k*r)), {k, 1, m}]], x]]; Sum[Binomial[d, p]*Plus @@ Plus @@ Outer[M[#1] M[#2] C[#1, #2]*2^(d - Length[#1] - Length[#2]) &, P[p], P[d - p], 1], {p, 0, d}]/(d! 2^d)]; AC[0]  = {1, 1};
%t A039754 AC /@ Range[0, 5] // Flatten (* _Jean-François Alcover_, Dec 15 2019, after _Robert A. Russell_ in A034189 *)
%t A039754 Table[ CoefficientList[ CycleIndexPolynomial[ GraphData[ {"Hypercube", n}, "AutomorphismGroup"], Array[Subscript[x, ##] &, 2^n]] /. Table[ Subscript[x, i] -> 1 + x^i, {i, 1, 2^n}], x], {n, 1,8}] // Grid (* _Geoffrey Critzer_, Jan 10 2020 *)
%Y A039754 Row sums give A000616. Cf. A052265.
%Y A039754 Rows give A034188, A034189, A034190, etc.
%Y A039754 Columns are A034198, A034199, A034200, etc.
%Y A039754 Diagonal is A276412.
%Y A039754 For other versions of this triangle see A171876, A039754, A276777.
%Y A039754 Cf. A171871.
%K A039754 nonn,tabf,nice,changed
%O A039754 0,8
%A A039754 _N. J. A. Sloane_
%E A039754 Corrected and extended by _Vladeta Jovovic_, Apr 20 2000
%E A039754 Entry revised by _N. J. A. Sloane_, Sep 19 2016
%E A039754 T(0, 1) = 1 inserted. (There are two 0-ary functions.) - _Tilman Piesk_, Jan 10 2023