A188457 -id:A188457 - cp's OEIS frontend

A003024 Number of acyclic digraphs (or DAGs) with n labeled nodes.

1, 1, 3, 25, 543, 29281, 3781503, 1138779265, 783702329343, 1213442454842881, 4175098976430598143, 31603459396418917607425, 521939651343829405020504063, 18676600744432035186664816926721, 1439428141044398334941790719839535103, 237725265553410354992180218286376719253505

Offset: 0

N. J. A. Sloane

Also the number of n X n real (0,1)-matrices with all eigenvalues positive. - Conjectured by Eric W. Weisstein, Jul 10 2003 and proved by McKay et al. 2003, 2004
Also the number of n X n real (0,1)-matrices with permanent equal to 1, up to permutation of rows/columns, cf. A089482. - Vladeta Jovovic, Oct 28 2009
Also the number of nilpotent elements in the semigroup of binary relations on [n]. - Geoffrey Critzer, May 26 2022
From Gus Wiseman, Jan 01 2024: (Start)
Also the number of sets of n nonempty subsets of {1..n} such that there is a unique way to choose a different element from each. For example, non-isomorphic representatives of the a(3) = 25 set-systems are:
  {{1},{2},{3}}
  {{1},{2},{1,3}}
  {{1},{2},{1,2,3}}
  {{1},{1,2},{1,3}}
  {{1},{1,2},{2,3}}
  {{1},{1,2},{1,2,3}}
These set-systems have ranks A367908, subset of A367906, for multisets A368101.
The version for no ways is A368600, any length A367903, ranks A367907.
The version for at least one way is A368601, any length A367902.
(End)

			For n = 2 the three (0,1)-matrices are {{{1, 0}, {0, 1}}, {{1, 0}, {1, 1}}, {{1, 1}, {0, 1}}}.

Archer, K., Gessel, I. M., Graves, C., & Liang, X. (2020). Counting acyclic and strong digraphs by descents. Discrete Mathematics, 343(11), 112041.
S. R. Finch, Mathematical Constants, Cambridge, 2003, p. 310.
F. Harary and E. M. Palmer, Graphical Enumeration, Academic Press, NY, 1973, p. 19, Eq. (1.6.1).
R. W. Robinson, Counting labeled acyclic digraphs, pp. 239-273 of F. Harary, editor, New Directions in the Theory of Graphs. Academic Press, NY, 1973.
N. J. A. Sloane and Simon Plouffe, The Encyclopedia of Integer Sequences, Academic Press, 1995 (includes this sequence).
R. P Stanley, Enumerative Combinatorics I, 2nd. ed., p. 322.

Alois P. Heinz, Table of n, a(n) for n = 0..77 (first 41 terms from T. D. Noe)
T. E. Allen, J. Goldsmith, and N. Mattei, Counting, Ranking, and Randomly Generating CP-nets, 2014.
Huantian Cao, AutoGF: An Automated System to Calculate Coefficients of Generating Functions, thesis, 2002.
Huantian Cao, AutoGF: An Automated System to Calculate Coefficients of Generating Functions, thesis, 2002 [Local copy, with permission]
Eunice Y.-J. Chen, A. Choi, and A. Darwiche, On Pruning with the MDL Score, JMLR: Workshop and Conference Proceedings vol 52, 98-109, 2016.
S. Engstrom, Random acyclic orientations of graphs, Master's thesis written at the department of Mathematics at the Royal Institute of Technology (KTH) in Stockholm, Jan. 2013.
Zehao Jin, Mario Pasquato, Benjamin L. Davis, Tristan Deleu, Yu Luo, Changhyun Cho, Pablo Lemos, Laurence Perreault-Levasseur, Yoshua Bengio, Xi Kang, Andrea Valerio Maccio, and Yashar Hezaveh, A Data-driven Discovery of the Causal Connection between Galaxy and Black Hole Evolution, arXiv:2410.00965 [astro-ph.GA], 2024. See p. 33.
Zehao Jin, Mario Pasquato, Benjamin L. Davis, Andrea V. Macciò, and Yashar Hezaveh, Beyond Causal Discovery for Astronomy: Learning Meaningful Representations with Independent Component Analysis, arXiv:2410.14775 [astro-ph.GA], 2024. See pp. 2, 4, 10.
Zehao Jin, Mario Pasquato, Benjamin L. Davis, Tristan Deleu, Yu Luo, Changhyun Cho, Pablo Lemos, Laurence Perreault-Levasseur, Yoshua Bengio, and Xi Kang, Causal Discovery in Astrophysics: Unraveling Supermassive Black Hole and Galaxy Coevolution, Astrophys. J. (2025) Vol. 979, 212. See 4.1.
P. L. Krapivsky, Hiring Strategies, arXiv:2412.10490 [cs.GT], 2024. See p. 12.
Qipeng Kuang, Ondřej Kuželka, Yuanhong Wang, and Yuyi Wang, Bridging Weighted First Order Model Counting and Graph Polynomials, arXiv:2407.11877 [cs.LO], 2024. See p. 33.
Jack Kuipers and Giusi Moffa, Uniform generation of random acyclic digraphs, arXiv preprint arXiv:1202.6590 [stat.CO], 2012. - _N. J. A. Sloane_, Sep 14 2012
Laphou Lao, Zecheng Li, Songlin Hou, Bin Xiao, Songtao Guo, and Yuanyuan Yang, A Survey of IoT Applications in Blockchain Systems: Architecture, Consensus and Traffic Modeling, ACM Computing Surveys (CSUR, 2020) Vol. 53, No. 1, Article No. 18.
Tobias Ellegaard Larsen, Claus Thorn Ekstrøm, and Anne Helby Petersen, Score-Based Causal Discovery with Temporal Background Information, arXiv:2502.06232 [stat.ME], 2025. See p. 9.
Daniel Mallia, Towards an Unsupervised Bayesian Network Pipeline for Explainable Prediction, Decision Making and Discovery, Master's Thesis, CUNY Hunter College (2023).
B. D. McKay, F. E. Oggier, G. F. Royle, N. J. A. Sloane, I. M. Wanless and H. S. Wilf, Acyclic digraphs and eigenvalues of (0,1)-matrices, J. Integer Sequences, 7 (2004), #04.3.3.
B. D. McKay, F. E. Oggier, G. F. Royle, N. J. A. Sloane, I. M. Wanless and H. S. Wilf, Acyclic digraphs and eigenvalues of (0,1)-matrices, arXiv:math/0310423 [math.CO], Oct 28 2003.
A. Motzek and R. Möller, Exploiting Innocuousness in Bayesian Networks, Preprint 2015.
Yisu Peng, Y. Jiang, and P. Radivojac, Enumerating consistent subgraphs of directed acyclic graphs: an insight into biomedical ontologies, arXiv preprint arXiv:1712.09679 [cs.DS], 2017.
J. Peters, J. Mooij, D. Janzing, and B. Schölkopf, Causal Discovery with Continuous Additive Noise Models, arXiv preprint arXiv:1309.6779 [stat.ML], 2013.
R. W. Robinson, Enumeration of acyclic digraphs, Manuscript. (Annotated scanned copy)
V. I. Rodionov, On the number of labeled acyclic digraphs, Disc. Math. 105 (1-3) (1992) 319-321
I. Shpitser, T. S. Richardson, J. M. Robins and R. Evans, Parameter and Structure Learning in Nested Markov Models, arXiv preprint arXiv:1207.5058 [stat.ML], 2012.
I. Shpitser, R. J. Evans, T. S. Richardson, and J. M. Robins, Introduction to nested Markov models, Behaviormetrika, Behaviormetrika Vol. 41, No. 1, 2014, 3-39.
R. P. Stanley, Acyclic orientation of graphs, Discrete Math. 5 (1973), 171-178. North Holland Publishing Company.
Christian Toth, Christian Knoll, Franz Pernkopf, and Robert Peharz, Rao-Blackwellising Bayesian Causal Inference, arXiv:2402.14781 [cs.LG], 2024.
Sumanth Varambally, Yi-An Ma, and Rose Yu, Discovering Mixtures of Structural Causal Models from Time Series Data, arXiv:2310.06312 [cs.LG], 2023.
S. Wagner, Asymptotic enumeration of extensional acyclic digraphs, in Proceedings of the SIAM Meeting on Analytic Algorithmics and Combinatorics (ANALCO12).
Daniel Waxman, Kurt Butler, and Petar M. Djuric, Dagma-DCE: Interpretable, Non-Parametric Differentiable Causal Discovery, arXiv:2401.02930 [cs.LG], 2024.
Eric Weisstein's World of Mathematics, (0,1)-Matrix
Eric Weisstein's World of Mathematics, Acyclic Digraph
Eric Weisstein's World of Mathematics, Positive Eigenvalued Matrix
Eric Weisstein's World of Mathematics, Weisstein's Conjecture
Jun Wu and Mathias Drton, Partial Homoscedasticity in Causal Discovery with Linear Models, arXiv:2308.08959 [math.ST], 2023.
Chris Ying, Enumerating Unique Computational Graphs via an Iterative Graph Invariant, arXiv:1902.06192 [cs.DM], 2019.
Index entries for sequences related to binary matrices

Cf. A086510, A081064 (refined by # arcs), A307049 (by # descents).
Cf. A055165, which counts nonsingular {0, 1} matrices and A085656, which counts positive definite {0, 1} matrices.
Cf. A188457, A135079, A137435 (acyclic 3-multidigraphs), A188490.
For a unique sink we have A003025.
The unlabeled version is A003087.
These are the reverse-alternating sums of rows of A046860.
The weakly connected case is A082402.
A reciprocal version is A334282.
Row sums of A361718.
Cf. A003465, A058877, A058891, A059201, A088957, A133686, A323818.

p:=evalf(solve(sum((-1)^n*x^n/(n!*2^(n*(n-1)/2)), n=0..infinity) = 0, x), 50); M:=evalf(sum((-1)^(n+1)*p^n/((n-1)!*2^(n*(n-1)/2)), n=1..infinity), 40); # program for evaluation of constants p and M in the asymptotic formula, Vaclav Kotesovec, Dec 09 2013

a[0] = a[1] = 1; a[n_] := a[n] = Sum[ -(-1)^k * Binomial[n, k] * 2^(k*(n-k)) * a[n-k], {k, 1, n}]; Table[a[n], {n, 0, 13}](* Jean-François Alcover, May 21 2012, after PARI *)
Table[2^(n*(n-1)/2)*n! * SeriesCoefficient[1/Sum[(-1)^k*x^k/k!/2^(k*(k-1)/2),{k,0,n}],{x,0,n}],{n,0,20}] (* Vaclav Kotesovec, May 19 2015 *)
Table[Length[Select[Subsets[Subsets[Range[n]],{n}],Length[Select[Tuples[#],UnsameQ@@#&]]==1&]],{n,0,5}] (* Gus Wiseman, Jan 01 2024 *)

a(n)=if(n<1,n==0,sum(k=1,n,-(-1)^k*binomial(n,k)*2^(k*(n-k))*a(n-k)))

{a(n)=polcoeff(1-sum(k=0, n-1, a(k)*x^k/(1+2^k*x+x*O(x^n))^(k+1)), n)} \\ Paul D. Hanna, Oct 17 2009

a(0) = 1; for n > 0, a(n) = Sum_{k=1..n} (-1)^(k+1)*C(n, k)*2^(k*(n-k))*a(n-k).
1 = Sum_{n>=0} a(n)*exp(-2^n*x)*x^n/n!. - Vladeta Jovovic, Jun 05 2005
a(n) = Sum_{k=1..n} (-1)^(n-k)*A046860(n,k) = Sum_{k=1..n} (-1)^(n-k)*k!*A058843(n,k). - Vladeta Jovovic, Jun 20 2008
1 = Sum_{n=>0} a(n)*x^n/(1 + 2^n*x)^(n+1). - Paul D. Hanna, Oct 17 2009
1 = Sum_{n>=0} a(n)*C(n+m-1,n)*x^n/(1 + 2^n*x)^(n+m) for m>=1. - Paul D. Hanna, Apr 01 2011
log(1+x) = Sum_{n>=1} a(n)*(x^n/n)/(1 + 2^n*x)^n. - Paul D. Hanna, Apr 01 2011
Let E(x) = Sum_{n >= 0} x^n/(n!*2^C(n,2)). Then a generating function for this sequence is 1/E(-x) = Sum_{n >= 0} a(n)*x^n/(n!*2^C(n,2)) = 1 + x + 3*x^2/(2!*2) + 25*x^3/(3!*2^3) + 543*x^4/(4!*2^6) + ... (Stanley). Cf. A188457. - Peter Bala, Apr 01 2013
a(n) ~ n!*2^(n*(n-1)/2)/(M*p^n), where p = 1.488078545599710294656246... is the root of the equation Sum_{n>=0} (-1)^n*p^n/(n!*2^(n*(n-1)/2)) = 0, and M = Sum_{n>=1} (-1)^(n+1)*p^n/((n-1)!*2^(n*(n-1)/2)) = 0.57436237330931147691667... Both references to the article "Acyclic digraphs and eigenvalues of (0,1)-matrices" give the wrong value M=0.474! - Vaclav Kotesovec, Dec 09 2013 [Response from N. J. A. Sloane, Dec 11 2013: The value 0.474 has a typo, it should have been 0.574. The value was taken from Stanley's 1973 paper.]
exp( Sum_{n >= 1} a(n)*x^n/n ) = 1 + x + 2*x^2 + 10*x^3 + 146*x^4 + 6010*x^5 + ... appears to have integer coefficients (cf. A188490). - Peter Bala, Jan 14 2016

A135079 E.g.f. A(x) = Sum_{n>=0} exp(3^nx)x^n/n!.

Original entry on oeis.org

1, 2, 8, 56, 704, 15392, 593408, 39691136, 4650143744, 944100803072, 334651494268928, 205435333440321536, 219775256161359233024, 407034554694060677537792, 1312205966809501720566038528

Offset: 0

Paul D. Hanna, Nov 24 2007

a(n) is the number of labeled graphs with (at most) 2 colors of vertices where vertices of the same color are never adjacent and the graphs may have up to 2 types of edges. - Geoffrey Critzer, Apr 20 2020

G. C. Greubel, Table of n, a(n) for n = 0..75

Cf. A047863 (variant). A188457.

Table[Sum[Binomial[n,k]*3^(k*(n-k)),{k,0,n}],{n,0,20}] (* Vaclav Kotesovec, Jun 24 2013 *)

{a(n)=sum(k=0,n,binomial(n,k)*3^(k*(n-k)))}

/* E.g.f.: */ {a(n)=n!*polcoeff(sum(k=0,n,exp(3^k*x +x*O(x^n))*x^k/k!),n)}

{a(n)=polcoeff(sum(k=0,n,x^k/(1 - 3^k*x +x*O(x^n))^(k+1)),n)} \\ Paul D. Hanna, Aug 08 2009

a(n) = Sum_{k=0..n} C(n, k)*3^(k*(n-k)).
O.g.f.: A(x) = Sum_{n>=0} x^n/(1 - 3^n*x)^(n+1). - Paul D. Hanna, Aug 08 2009
Let E(x) = sum {n >= 0} x^n/(n!*3^C(n,2)). Then a generating function for this sequence is E(x)^2 = sum {n >= 0} a(n)*x^n/(n!*3^C(n,2)) = 1 + 2*x + 8*x^2/(2!*3) + 56*x^3/(3!*3^3) + 704*x^4/(4!*3^6) + .... Cf. A188457. - Peter Bala, Apr 01 2013
a(n) ~ c * 3^(n^2/4)*2^(n+1/2)/sqrt(Pi*n), where c = Sum_{k = -infinity..infinity} 3^(-k^2) = 1.6914596816817... if n is even and c = Sum_{k = -infinity..infinity} 3^(-(k+1/2)^2) = 1.69061120307521... if n is odd. - Vaclav Kotesovec, Jun 24 2013

A137435 Acyclic 3-multidigraphs on n nodes.

Original entry on oeis.org

1, 1, 7, 289, 63487, 69711361, 367404658687, 9036285693861889, 1015983915928423497727, 514039127264534042076119041, 1155907276780291114251550828003327, 11436746463485293365165228859824053157889, 493776641438913029616304251647570171691844763647

Offset: 0

Jonathan Vos Post, Apr 17 2008

nonn

This is the 2nd row of Table 1, p. 3 in Liskovets. The first row is A003024.

			From _Paul D. Hanna_, Apr 01 2011: (Start)
Illustration of the generating functions.
E.g.f.: 1 = exp(-x) + exp(-4*x)*x + 7*exp(-16*x)*x^2/2! + 289*exp(-64*x)*x^3/3! + ...
L.g.f.: log(1+x) = x/(1+4*x) + 7*(x^2/2)/(1+16*x)^2 + 289*(x^3/3)/(1+64*x)^3 + ...
G.f.: 1 = 1/(1+x) + 1*x/(1+4*x)^2 + 7*x^2/(1+16*x)^3 + 289*x^3/(1+64*x)^4 + ...
G.f.: 1 = 1/(1+x)^2 + 1*2*x/(1+4*x)^3 + 7*3*x^2/(1+16*x)^4 + 289*4*x^3/(1+64*x)^5 + ...
G.f.: 1 = 1/(1+x)^3 + 1*3*x/(1+4*x)^4 + 7*6*x^2/(1+16*x)^5 + 289*10*x^3/(1+64*x)^6 + ... (End)

Vincenzo Librandi, Table of n, a(n) for n = 0..55
Valery A. Liskovets, More on counting acyclic digraphs, arXiv:0804.2496 [math.CO], 2008.

Cf. A003024, A188457.

a[n_] := a[n] = Sum[(-1)^(k+1)*Binomial[n, k]*4^(k*(n-k))*a[n-k], {k, 1, n}]; a[0]=1; Table[a[n], {n, 0, 12}] (* Jean-François Alcover, Dec 15 2014, after Paul D. Hanna *)

{a(n)=polcoeff(1-sum(k=0, n-1, a(k)*x^k/(1+4^k*x+x*O(x^n))^(k+1)), n)} \\ Paul D. Hanna, Oct 17 2009

/* Holds for m>=1: */
{a(n)=local(m=1); polcoeff(1-sum(k=0, n-1, a(k)*binomial(m+k-1, k)*x^k/(1+4^k*x+x*O(x^n))^(k+m)), n)/binomial(m+n-1, n)} \\ Paul D. Hanna, Apr 01 2011

/* Recurrence: */
{a(n)=if(n<1, n==0, sum(k=1, n, -(-1)^k*binomial(n, k)*4^(k*(n-k))*a(n-k)))} \\ Paul D. Hanna, Apr 01 2011

/* E.g.f.: */
{a(n)=n!*polcoeff(1-sum(k=0, n-1, a(k)*exp(-4^k*x+x*O(x^n))*x^k/k!), n)} \\ Paul D. Hanna, Apr 01 2011

1 = Sum_{n>=0} a(n)*exp(-4^n*x)*x^n/n!. - Vladeta Jovovic, Apr 22 2008
1 = Sum_{n>=0} a(n)*x^n/(1 + 4^n*x)^(n+1). - Paul D. Hanna, Oct 17 2009
1 = Sum_{n>=0} a(n)*binomial(n+m-1,n)*x^n/(1 + 4^n*x)^(n+m) for m >= 1. - Paul D. Hanna, Apr 01 2011
log(1+x) = Sum_{n>=1} a(n)*(x^n/n)/(1 + 4^n*x)^n. - Paul D. Hanna, Apr 01 2011
a(n) = Sum_{k=1..n} (-1)^(k+1)*C(n, k)*4^(k*(n-k))*a(n-k) for n > 0 with a(0)=1. - Paul D. Hanna, Apr 01 2011

More terms from Vladeta Jovovic, Apr 22 2008

Offset changed to 0 by Paul D. Hanna, Apr 01 2011

A339768 Square array read by descending antidiagonals. T(n,k) is the number of acyclic k-multidigraphs on n labeled vertices, n>=0,k>=0.

Original entry on oeis.org

1, 1, 1, 1, 1, 1, 1, 1, 3, 1, 1, 1, 5, 25, 1, 1, 1, 7, 109, 543, 1, 1, 1, 9, 289, 9449, 29281, 1, 1, 1, 11, 601, 63487, 3068281, 3781503, 1, 1, 1, 13, 1081, 267249, 69711361, 3586048685, 1138779265, 1

Offset: 0

Geoffrey Critzer, Feb 21 2021

Here, a k-multidigraph is a directed graph where up to k arcs (directed edges) are allowed to join vertex pairs. The arcs have no identity, i.e., they are indistinguishable except for the ordered pair of distinct vertices that they join.

			  1,     1,       1,        1,         1,          1, ...
  1,     1,       1,        1,         1,          1, ...
  1,     3,       5,        7,         9,         11, ...
  1,    25,     109,      289,       601,       1081, ...
  1,   543,    9449,    63487,    267249,     849311, ...
  1, 29281, 3068281, 69711361, 742650001, 5004309601, ...

Seiichi Manyama, Antidiagonals n = 0..50, flattened
R. P. Stanley, Acyclic orientation of graphs, Discrete Math. 5 (1973), 171-178.

Cf. A003024 (column k=1), A188457 (column k=2), A137435 (column k=3).

Main diagonal gives A354962.

nn = 5; Table[g[n_] := q^Binomial[n, 2] n!; e[z_] := Sum[z^k/g[k], {k, 0, nn}];
   Table[g[n], {n, 0, nn}] CoefficientList[Series[1/e[-z], {z, 0, nn}], z], {q, 1, nn + 1}] //Transpose // Grid

Let E(x) = Sum_{n>=0} x^n/(n!*(k+1)^binomial(n,2)). Then 1/E(-x) = Sum_{n>=0} T(n,k)x^n/(n!*(k+1)^binomial(n,2)).

T(0,k) = 1 and T(n,k) = Sum_{j=1..n} (-1)^(j+1) * (k+1)^(j*(n-j)) * binomial(n,j) * T(n-j,k) for n > 0. - Seiichi Manyama, Jun 13 2022

A188455 G.f.: 1 = Sum_{n>=0} a(n)x^n/(1 + 2^nx)^(2n+1).

Original entry on oeis.org

1, 1, 5, 77, 3191, 332481, 83495679, 49089025473, 66142622730623, 200954040909283841, 1359156203343916471295, 20253823024219712679748609, 659335186924510858208484730879, 46554554840488755704034417937268737

Offset: 0

Paul D. Hanna, Mar 31 2011

nonn

G.f. satisfies a variant of an identity of the Catalan numbers (A000108):
1 = Sum_{n>=0} A000108(n)*x^n/(1 + x)^(2n+1).
Also, g.f. satisfies a variant of an identity involving A003024:
1 = Sum_{n>=0} A003024(n)*x^n/(1 + 2^n*x)^(n+1),
where A003024(n) is the number of acyclic digraphs with n labeled nodes.

			G.f.: 1 = 1/(1+x) + x/(1+2*x)^3 + 5*x^2/(1+4*x)^5 + 77*x^3/(1+8*x)^7 + 3191*x^4/(1+16*x)^9 + 332481*x^5/(1+32*x)^11 +...

Cf. A188456, A188457, A003024.

{a(n)=polcoeff(1-sum(k=0, n-1, a(k)*x^k/(1+2^k*x+x*O(x^n))^(2*k+1)), n)}

A188456 G.f.: 1 = Sum_{n>=0} a(n)x^n(1 - 2^n*x)^(n+1).

Original entry on oeis.org

1, 1, 4, 44, 1216, 80640, 12460032, 4393091072, 3479212916736, 6113821454237696, 23602899265140031488, 198562423940692641316864, 3615246879908004653107773440, 141631725381846630255125115961344

Offset: 0

Paul D. Hanna, Mar 31 2011

nonn

G.f. satisfies a variant of an identity of the Catalan numbers (A000108):

1 = Sum_{n>=0} A000108(n)*x^n*(1 - x)^(n+1).

			G.f.: 1 = (1-x) + x*(1-2*x)^2 + 4*x^2*(1-4*x)^3 + 44*x^3*(1-8*x)^4 + 1216*x^4*(1-16*x)^5 + 80640*x^5*(1-32*x)^6 + ...

Cf. A188455, A188457, A188458.

a[0] = 1; a[n_] := a[n] = SeriesCoefficient[1-Sum[a[k]*x^k*(1-2^k*x)^(k+1), {k, 0, n-1}], {x, 0, n}];
Table[a[n], {n, 0, 13}] (* Jean-François Alcover, Dec 09 2017 *)

{a(n)=polcoeff(1-sum(k=0, n-1, a(k)*x^k*(1-2^k*x+x*O(x^n))^(k+1)), n)}

0 = Sum_{k=0..[(n+1)/2]} (-1)^k*C(n-k+1,k)*2^(k*(n-k))*a(n-k) for n > 0.

A355070 G.f.: Sum_{n>=0} a(n)x^n/(n!3^(n(n-1)/2)) = log( Sum_{n>=0} x^n/(n!3^(n*(n-1)/2)) ).

Original entry on oeis.org

0, 1, -2, 28, -1808, 469072, -456745472, 1601325615808, -19650153075181568, 826737899840505194752, -117393483573257494026125312, 55564698792825562646890851908608, -86789641569440259960965030826164092928

Offset: 0

Seiichi Manyama, Jun 18 2022

sign

Cf. A134531, A355071.

Cf. A188457, A355073.

a(n) = n!*3^(n*(n-1)/2)*polcoef(log(sum(k=0, n, x^k/(k!*3^(k*(k-1)/2)))+x*O(x^n)), n);

a_vector(n) = my(v=vector(n+1)); v[1]=0; for(i=1, n, v[i+1]=1-sum(j=1, i-1, 3^(j*(i-j))*binomial(i-1, j)*v[i-j+1])); v;

a(0) = 0; a(n) = 1 - Sum_{k=1..n-1} 3^(k*(n-k)) * binomial(n-1,k) * a(n-k).

cp's OEIS Frontend

A003024 Number of acyclic digraphs (or DAGs) with n labeled nodes.

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A135079 E.g.f. A(x) = Sum_{n>=0} exp(3^n*x)*x^n/n!.

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A137435 Acyclic 3-multidigraphs on n nodes.

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PARI

PARI

PARI

Formula

Extensions

A339768 Square array read by descending antidiagonals. T(n,k) is the number of acyclic k-multidigraphs on n labeled vertices, n>=0,k>=0.

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Mathematica

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A188455 G.f.: 1 = Sum_{n>=0} a(n)*x^n/(1 + 2^n*x)^(2n+1).

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PARI

A188456 G.f.: 1 = Sum_{n>=0} a(n)*x^n*(1 - 2^n*x)^(n+1).

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Mathematica

PARI

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A355070 G.f.: Sum_{n>=0} a(n)*x^n/(n!*3^(n*(n-1)/2)) = log( Sum_{n>=0} x^n/(n!*3^(n*(n-1)/2)) ).

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A135079 E.g.f. A(x) = Sum_{n>=0} exp(3^nx)x^n/n!.

A188455 G.f.: 1 = Sum_{n>=0} a(n)x^n/(1 + 2^nx)^(2n+1).

A188456 G.f.: 1 = Sum_{n>=0} a(n)x^n(1 - 2^n*x)^(n+1).

A355070 G.f.: Sum_{n>=0} a(n)x^n/(n!3^(n(n-1)/2)) = log( Sum_{n>=0} x^n/(n!3^(n*(n-1)/2)) ).