Original entry on oeis.org
1, 1, 8, 78, 876, 10956, 149472, 2195208, 34398288, 571525200, 10022997888, 184897670112, 3578224662720, 72486450479808, 1534267158087168, 33877135427154048, 779208751651730688, 18645519786163266816
Offset: 0
(1/6)*(log(1 + 6*x + 42*x^2 + 336*x^3 + ... + (n+5)!/5!)*x^n + ...)
= x + 8/2*x^2 + 78/3*x^3 + 876/4*x^4 + 10956/5*x^5 + ...
-
m = 18; (-1/(6x)) ContinuedFractionK[-i x, 1 + i x, {i, 6, m+5}] + O[x]^m // CoefficientList[#, x]& (* Jean-François Alcover, Nov 02 2019 *)
-
{a(n)=if(n<0,0,if(n==0,1, (n/6)*polcoeff(log(sum(m=0,n,(m+5)!/5!*x^m) + x*O(x^n)),n)))} \\ fixed by Vaclav Kotesovec, Jul 27 2015
A113869
Coefficients in asymptotic expansion of probability that a random pair of elements from the alternating group A_k generates all of A_k.
Original entry on oeis.org
1, -1, -1, -4, -23, -171, -1542, -16241, -194973, -2622610, -39027573, -636225591, -11272598680, -215668335091, -4431191311809, -97316894892644, -2275184746472827, -56421527472282127, -1479397224086870294, -40897073524132164189, -1188896226524012279617
Offset: 0
- Vaclav Kotesovec, Table of n, a(n) for n = 0..420
- L. Babai, The probability of generating the symmetric group, J. Combin. Theory, A52 (1989), 148-153.
- J. Bovey and A. Williamson, The probability of generating the symmetric group, Bull. London Math. Soc. 10 (1978) 91-96.
- J. D. Dixon, The probability of generating the symmetric group, Math. Z. 110 (1969) 199-205.
- J. D. Dixon, Asymptotics of Generating the Symmetric and Alternating Groups, Electronic Journal of Combinatorics, vol 11(2), R56.
- Thibault Godin, An analogue to Dixon's theorem for automaton groups, arXiv preprint arXiv:1610.03301 [math.GR], 2016.
- Richard J. Martin, and Michael J. Kearney, Integral representation of certain combinatorial recurrences, Combinatorica: 35:3 (2015), 309-315.
-
A003319[n_] := A003319[n] = n! - Sum[ k!*A003319[n-k], {k, 1, n-1}]; a[n_] := -Sum[ A003319[i]*StirlingS2[n-1, i-1], {i, 1, n}]; a[0] = 1; Table[a[n], {n, 0, 20}] (* Jean-François Alcover, Dec 11 2012, after N. J. A. Sloane *)
A059332
Determinant of n X n matrix A defined by A[i,j] = (i+j-1)! for 1 <= i,j <= n.
Original entry on oeis.org
1, 1, 2, 24, 3456, 9953280, 859963392000, 3120635156889600000, 634153008009974906880000000, 9278496603801318870491332608000000000, 12218100099725239100847669366019325952000000000000, 1769792823810713244721831122736499011207487815680000000000000000
Offset: 0
Noam Katz (noamkj(AT)hotmail.com), Jan 26 2001
a(4) = 3456 because the relevant matrix is {1 2 6 24 / 2 6 24 120 / 6 24 120 720 / 24 120 720 5040 } and the determinant is 3456.
- Alois P. Heinz, Table of n, a(n) for n = 0..32
- Paul Barry, Jacobsthal Decompositions of Pascal's Triangle, Ternary Trees, and Alternating Sign Matrices, Journal of Integer Sequences, 19, 2016, #16.3.5.
- Googology Wiki, Bouncing Factorial
-
with(linalg): Digits := 500: A059332 := proc(n) local A, i, j: A := array(1..n,1..n): for i from 1 to n do for j from 1 to n do A[i,j] := (i+j-1)! od: od: RETURN(det(A)) end: for n from 1 to 20 do printf(`%d,`, A059332(n)) od;
# second Maple program:
a:= proc(n) option remember;
`if`(n=0, 1, a(n-1)*n!^2/n)
end:
seq(a(n), n=0..12); # Alois P. Heinz, Apr 29 2020
-
Table[n! BarnesG[n+1]^2, {n, 1, 10}] (* Jean-François Alcover, Sep 19 2016 *)
-
A059332(n)=matdet(matrix(n,n,i,j,(i+j-1)!)) \\ M. F. Hasler, Nov 03 2013
-
a(n) = 2^binomial(n,2)*prod(k=1,n-1, binomial(k+2,2)^(n-1-k)) \\ Ralf Stephan, Nov 04 2013
-
def mono_choices(a,b,n)
n - [a,b].max
end
def all_mono_choices(n)
accum =1
0.upto(n-1) do |i|
0.upto(n-1) do |j|
accum = accum * mono_choices(i,j,n)
end
end
accum
end
1.upto(12) do |k|
puts all_mono_choices(k)
end # Chad Brewbaker, Nov 03 2013
Offset corrected. Comment and formula aligned with new offset by
Johannes W. Meijer, Jun 24 2009
A089949
Triangle T(n,k), read by rows, given by [0, 1, 0, 1, 0, 1, 0, 1, 0, 1, 0, ...] DELTA [1, 1, 2, 2, 3, 3, 4, 4, 5, 5, 6, 6, ...] where DELTA is the operator defined in A084938.
Original entry on oeis.org
1, 0, 1, 0, 1, 2, 0, 1, 6, 6, 0, 1, 12, 34, 24, 0, 1, 20, 110, 210, 120, 0, 1, 30, 270, 974, 1452, 720, 0, 1, 42, 560, 3248, 8946, 11256, 5040, 0, 1, 56, 1036, 8792, 38338, 87504, 97296, 40320, 0, 1, 72, 1764, 20580, 129834, 463050, 920184, 930960, 362880
Offset: 0
Triangle begins:
1;
0, 1;
0, 1, 2;
0, 1, 6, 6;
0, 1, 12, 34, 24;
0, 1, 20, 110, 210, 120;
0, 1, 30, 270, 974, 1452, 720; ...
-
m = 10;
gf = (1/x)*(1-1/(1+Sum[Product[(1+k*y), {k, 0, n-1}]*x^n, {n, 1, m}]));
CoefficientList[#, y]& /@ CoefficientList[gf + O[x]^m, x] // Flatten (* Jean-François Alcover, May 11 2019 *)
-
T(n,k)=if(nPaul D. Hanna, Aug 16 2005
A027837
Number of subgroups of index n in free group of rank 3.
Original entry on oeis.org
1, 7, 97, 2143, 68641, 3011263, 173773153, 12785668351, 1169623688353, 130305512589247, 17376934722756577, 2733655173624167551, 501034099176714373921, 105847486567006696384831
Offset: 1
- P. de la Harpe, Topics in Geometric Group Theory, Univ. Chicago Press, 2000, p. 23.
- R. P. Stanley, Enumerative Combinatorics, Cambridge, Vol. 2, 1999; see Problem 5.13(b).
- Reinhard Zumkeller, Table of n, a(n) for n = 1..250
- M. Hall, Subgroups of finite index in free groups, Canad. J. Math., 1 (1949), 187-190.
- V. A. Liskovets and A. Mednykh, Enumeration of subgroups in the fundamental groups of orientable circle bundles over surfaces, Commun. in Algebra, 28, No. 4 (2000), 1717-1738.
-
a027837 n = a027837_list !! (n-1)
a027837_list = f 1 [] where
f x ys = y : f (x + 1) (y : ys) where
y = a001044 x * x - sum (zipWith (*) ys $ tail a001044_list)
-- Reinhard Zumkeller, Sep 05 2015
-
a[n_] := a[n] = n*n!^2 - Sum [k!^2*a[n-k], {k, 1, n-1}]; Table[ a[n], {n, 1, 14}] (* Jean-François Alcover, Dec 13 2011, after formula *)
-
{a(n)=n*polcoeff(log(sum(k=0,n,k!^2*x^k)+x*O(x^n)),n)} \\ Paul D. Hanna, Apr 13 2009
More terms from Larry Reeves (larryr(AT)acm.org), Oct 05 2000
A077607
Convolutory inverse of the factorial sequence.
Original entry on oeis.org
1, -2, -2, -8, -44, -296, -2312, -20384, -199376, -2138336, -24936416, -314142848, -4252773824, -61594847360, -950757812864, -15586971531776, -270569513970944, -4959071121374720, -95721139472072192, -1941212789888952320, -41271304403571227648
Offset: 1
a(4)= -8 = -24*1-6*(-2)-2*(-2). (a(1),a(2),...,a(n))(*)(1,2,3!,...,n!)=(1,0,0,...,0), where (*) denotes convolution.
- Alois P. Heinz, Table of n, a(n) for n = 1..449
- Jean-Christophe Aval, Jean-Christophe Novelli, Jean-Yves Thibon, The # product in combinatorial Hopf algebras, dmtcs:2892 - Discrete Mathematics & Theoretical Computer Science, January 1, 2011, DMTCS Proceedings vol. AO, 23rd International Conference on Formal Power Series and Algebraic Combinatorics (FPSAC 2011).
- Richard J. Martin, and Michael J. Kearney, Integral representation of certain combinatorial recurrences, Combinatorica: 35:3 (2015), 309-315.
- Ioannis Michos, Christina Savvidou, Enumeration of super-strong Wilf equivalence classes of permutations, arXiv:1803.08818 [math.CO], 2018.
- Vincent Pilaud, V. Pons, Permutrees, arXiv preprint arXiv:1606.09643 [math.CO], 2016 (Unsigned version).
-
a:= proc(n) option remember; `if`(n=1, 1,
-add((n-i+1)!*a(i), i=1..n-1))
end:
seq(a(n), n=1..25); # Alois P. Heinz, Dec 20 2017
-
Clear[a]; a[1]=1; a[n_]:=a[n]=Sum[-(n-j+1)!*a[j],{j,1,n-1}]; Table[a[n],{n,1,20}] (* Vaclav Kotesovec, Jul 27 2015 *)
terms=21; 1/Sum[(k+1)!*x^k, {k, 0, terms}]+O[x]^terms // CoefficientList[#, x]& (* Jean-François Alcover, Dec 20 2017, after Vladeta Jovovic *)
-
def A077607_list(len):
R, C = [1], [1]+[0]*(len-1)
for n in (1..len-1):
for k in range(n, 0, -1):
C[k] = C[k-1] * (k+1)
C[0] = -sum(C[k] for k in (1..n))
R.append(C[0])
return R
print(A077607_list(21)) # Peter Luschny, Feb 28 2016
A049290
Array T(n,k) = number of subgroups of index k in free group of rank n, read by antidiagonals.
Original entry on oeis.org
1, 1, 1, 1, 3, 1, 1, 7, 13, 1, 1, 15, 97, 71, 1, 1, 31, 625, 2143, 461, 1, 1, 63, 3841, 54335, 68641, 3447, 1, 1, 127, 23233, 1321471, 8563601, 3011263, 29093, 1, 1, 255, 139777, 31817471, 1035045121, 2228419359, 173773153, 273343, 1, 1, 511, 839425
Offset: 1
Array T(n,k) (n >= 1, k >= 1) begins:
1, 1, 1, 1, 1, ...
1, 3, 13, 71, 461, ...
1, 7, 97, 2143, 68641, ...
1, 15, 625, 54335, 8563601, ...
- P. de la Harpe, Topics in Geometric Group Theory, Univ. Chicago Press, 2000, p. 23.
- J. H. Kwak and J. Lee, Enumeration of graph coverings, surface branched coverings and related group theory, in Combinatorial and Computational Mathematics (Pohang, 2000), ed. S. Hong et al., World Scientific, Singapore 2001, pp. 97-161.
- R. P. Stanley, Enumerative Combinatorics, Cambridge, Vol. 2, 1999; see Problem 5.13(b).
- Alois P. Heinz, Antidiagonals n = 1..37, flattened
- J. H. Kwak and J. Lee, Enumeration of graph coverings and surface branched coverings, Lecture Note Series 1 (2001), Com^2MaC-KOSEF, Korea. See chapter 3. [Broken link?]
- V. A. Liskovets and A. Mednykh, Enumeration of subgroups in the fundamental groups of orientable circle bundles over surfaces, Commun. in Algebra, 28, No. 4 (2000), 1717-1738.
-
T:= proc(n,k) option remember; k* k!^(n-1) -add(j!^(n-1) *T(n, k-j), j=1..k-1) end: seq(seq(T(d+1-k, k), k=1..d), d=1..10); # Alois P. Heinz, Oct 29 2009
-
nmax = 10; t[n_, k_] := t[n, k] = k*k!^(n-1) - Sum[j!^(n-1)*t[n, k-j], {j, 1, k-1}]; Flatten[ Table[ t[n-k+1, k], {n, 1, nmax}, {k, 1, n}]] (* Jean-François Alcover, Nov 09 2011, after Maple *)
A273526
Number of 123-avoiding indecomposable permutations.
Original entry on oeis.org
1, 1, 3, 11, 38, 127, 423, 1423, 4854, 16787, 58776, 208001, 742888, 2674427, 9694831, 35357655, 129644774, 477638683, 1767263172, 6564120401, 24466267000, 91482563619, 343059613628, 1289904147301, 4861946401428, 18367353072127, 69533550915978, 263747951750333, 1002242216651340, 3814986502092275
Offset: 1
- Indranil Ghosh, Table of n, a(n) for n = 1..1000
- A. L. L. Gao, S. Kitaev, P. B. Zhang. On pattern avoiding indecomposable permutations, arXiv:1605.05490 [math.CO], 2016.
- Murray Tannock, Equivalence classes of mesh patterns with a dominating pattern, MSc Thesis, Reykjavik Univ., May 2016.
-
a[n_] := CatalanNumber[n] - (n - 1)
Table[a[n], {n, 1, 30}] (* Alice L.L. Gao, May 24 2016 *)
-
a(n) = binomial(2*n,n)/(n+1) - n + 1; \\ Indranil Ghosh, Mar 04 2017
-
import math
f=math.factorial
def C(n,r): return f(n)/f(r)/f(n-r)
def Catalan(n): return C(2*n,n)/(n+1)
def A273526(n): return Catalan(n)-n+1 # Indranil Ghosh, Mar 04 2017
A321710
Triangle read by rows: T(n,k) is the number of rooted hypermaps of genus k with n darts.
Original entry on oeis.org
1, 3, 12, 1, 56, 15, 288, 165, 8, 1584, 1611, 252, 9152, 14805, 4956, 180, 54912, 131307, 77992, 9132, 339456, 1138261, 1074564, 268980, 8064, 2149888, 9713835, 13545216, 6010220, 579744, 13891584, 81968469, 160174960, 112868844, 23235300, 604800, 91287552, 685888171, 1805010948, 1877530740, 684173164, 57170880, 608583680, 5702382933, 19588944336, 28540603884, 16497874380, 2936606400, 68428800, 4107939840, 47168678571, 206254571236, 404562365316, 344901105444, 108502598960, 8099018496
Offset: 1
Triangle starts:
n\k [0] [1] [2] [3] [4] [5]
[1] 1;
[2] 3;
[3] 12, 1;
[4] 56, 15;
[5] 288, 165, 8;
[6] 1584, 1611, 252;
[7] 9152, 14805, 4956, 180;
[8] 54912, 131307, 77992, 9132;
[9] 339456, 1138261, 1074564, 268980, 8064;
[10] 2149888, 9713835, 13545216, 6010220, 579744;
[11] 13891584, 81968469, 160174960, 112868844, 23235300, 604800;
[12] 91287552, 685888171, 1805010948, 1877530740, 684173164, 57170880;
[13] ...
- Gheorghe Coserea, Rows n = 1..42, flattened
- Alain Giorgetti and Timothy R. S. Walsh, Enumeration of hypermaps of a given genus, Ars Math. Contemp. 15 (2018) 225-266.
- Timothy R. Walsh, Space-efficient generation of nonisomorphic maps and hypermaps
- T. R. Walsh, Space-Efficient Generation of Nonisomorphic Maps and Hypermaps, J. Int. Seq. 18 (2015) # 15.4.3.
- P. G. Zograf, Enumeration of Grothendieck's Dessins and KP Hierarchy, International Mathematics Research Notices, Volume 2015, Issue 24, 1 January 2015, 13533-13544.
- Peter Zograf, Enumeration of Grothendieck's Dessins and KP Hierarchy, arXiv:1312.2538 [math.CO], 2014.
-
l1[f_,n_] := Sum[(i-1)t[i]D[f,t[i-1]], {i,2,n}];
m1[f_,n_] := Sum[(i-1)t[j]t[i-j]D[f,t[i-1]] + j(i-j)t[i+1]D[f,t[j],t[i-j]], {i,2,n},{j,i-1}];
ff[1] = x^2 t[1];
ff[n_] := ff[n] = Simplify@(2x l1[ff[n-1],n] + m1[ff[n-1],n] + Sum[t[i+1]j(i-j)D[ff[k],t[j]]D[ff[n-1-k],t[i-j]], {i,2,n-1},{j,i-1},{k,n-2}]) / n;
row[n_]:=Reverse[CoefficientList[n ff[n] /. {t[_]->x}, x]][[;;;;2]][[;;Quotient[n+1,2]]];
Table[row[n], {n,14}] (* Andrei Zabolotskii, Jun 27 2025, after the PARI code *)
-
L1(f, N) = sum(i=2, N, (i-1)*t[i]*deriv(f, t[i-1]));
M1(f, N) = {
sum(i=2, N, sum(j=1, i-1, (i-1)*t[j]*t[i-j]*deriv(f, t[i-1]) +
j*(i-j)*t[i+1]*deriv(deriv(f, t[j]), t[i-j])));
};
F(N) = {
my(u='x, v='x, f=vector(N)); t=vector(N+1, n, eval(Str("t", n)));
f[1] = u*v*t[1];
for (n=2, N, f[n] = (u + v)*L1(f[n-1], n) + M1(f[n-1], n) +
sum(i=2, n-1, t[i+1]*sum(j=1, i-1,
j*(i-j)*sum(k=1, n-2, deriv(f[k], t[j])*deriv(f[n-1-k], t[i-j]))));
f[n] /= n);
f;
};
seq(N) = {
my(f=F(N), v=substvec(f, t, vector(#t, n, 'x)),
g=vector(#v, n, Polrev(Vec(n * v[n]))));
apply(p->Vecrev(substpol(p, 'x^2, 'x)), g);
};
concat(seq(14))
A084519
Number of indecomposable ground-state 3-ball juggling sequences of period n.
Original entry on oeis.org
1, 1, 3, 13, 47, 173, 639, 2357, 8695, 32077, 118335, 436549, 1610471, 5941181, 21917583, 80856053, 298285687, 1100404333, 4059496479, 14975869477, 55247410055, 203812962077, 751885445295, 2773777080149, 10232728055191
Offset: 1
- Carsten Elsner, Dominic Klyve and Erik R. Tou, A zeta function for juggling sequences, Journal of Combinatorics and Number Theory, Volume 4, Issue 1, 2012, pp. 1-13; ISSN 1942-5600
-
INVERTi([seq(A084509(n),n=1..80)]);
with(combinat); A084519 := proc(n) option remember; local c,i,k; A084509(n)-add(add(mul(A084519(i),i=c),c=composition(n,k)),k=2..n); end;
-
LinearRecurrence[{3,2,2},{1,1,3},30] (* Harvey P. Dale, Jul 20 2013 *)
Comments