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.

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A191365 Expansion of e.g.f. (1/(1-x))^exp(x).

Original entry on oeis.org

1, 1, 4, 18, 102, 695, 5485, 49077, 490308, 5404569, 65106103, 850535477, 11972432846, 180605413001, 2906109200293, 49678357272247, 898988188301320, 17167497793440977, 344991795682802331, 7277230501449340417, 160765066207998479698
Offset: 0

Views

Author

Vladimir Kruchinin, May 31 2011

Keywords

Comments

Exponential transform of A002104. - Seiichi Manyama, May 03 2022

Crossrefs

Programs

  • Mathematica
    CoefficientList[Series[(1/(1-x))^Exp[x], {x, 0, 20}], x]* Range[0, 20]! (* Vaclav Kotesovec, Jun 21 2013 *)
  • Maxima
    a(n):=sum(sum(binomial(n,i)*k^i*(-1)^(n-k-i)*stirling1(n-i,k),i,0,n-k),k,1,n);
    
  • PARI
    my(N=30, x='x+O('x^N)); Vec(serlaplace(1/(1-x)^exp(x))) \\ Seiichi Manyama, May 03 2022

Formula

a(n) = sum(k=1..n, sum(i=0..n-k, binomial(n,i)*k^i*(-1)^(n-k-i)*Stirling1(n-i,k))), n>0, a(0)=1.
a(n) ~ n! * n^(exp(1)-1)/Gamma(exp(1)) * (1-exp(1)*(exp(1)-1)*log(n)/n). - Vaclav Kotesovec, Jun 21 2013
a(0) = 1; a(n) = Sum_{k=1..n} A002104(k) * binomial(n-1,k-1) * a(n-k). - Seiichi Manyama, May 03 2022

A052863 Expansion of e.g.f. log(-1/(-1+x))*exp(x) - log(-1/(-1+x)).

Original entry on oeis.org

0, 0, 2, 6, 18, 65, 295, 1652, 11032, 85353, 749203, 7347384, 79564496, 942541041, 12121319327, 168145213732, 2502276609008, 39761200642225, 671855234838915, 12028625060491336, 227451564319791336, 4529507975800063337, 94751047516476943359, 2077192015403191663844
Offset: 0

Views

Author

encyclopedia(AT)pommard.inria.fr, Jan 25 2000

Keywords

Comments

Previous name was: A simple grammar.

Programs

  • Maple
    spec := [S,{B=Set(Z,1 <= card),C=Cycle(Z),S=Prod(B,C)},labeled]: seq(combstruct[count](spec,size=n), n=0..20);
  • Mathematica
    CoefficientList[Series[Log[-1/(-1+x)]*E^x-Log[-1/(-1+x)], {x, 0, 20}], x]* Range[0, 20]! (* Vaclav Kotesovec, Sep 29 2013 *)
  • PARI
    my(N=30, x='x+O('x^N)); concat([0, 0], Vec(serlaplace(-log(1-x)*(exp(x)-1)))) \\ Seiichi Manyama, May 13 2022
    
  • PARI
    a(n) = sum(k=0, n-2, k!*binomial(n, k+1)); \\ Seiichi Manyama, May 13 2022

Formula

E.g.f.: log(-1/(-1+x))*exp(x) - log(-1/(-1+x)).
Recurrence: {a(1)=0, a(3)=6, a(2)=2, (-n^3-2*n-3*n^2)*a(n)+(19*n+11*n^2+2*n^3+10)*a(n+1)+(-38*n-12*n^2-n^3-36)*a(n+2)+(41+26*n+4*n^2)*a(n+3)+(-17-5*n)*a(n+4)+2*a(n+5), a(4)=18, a(5)=65}
a(n) = A002104(n)-(n-1)!. - Vladeta Jovovic, Apr 03 2005
a(n) ~ (n-1)! * (exp(1)-1). - Vaclav Kotesovec, Sep 29 2013
a(n) = Sum_{k=0..n-2} k! * binomial(n,k+1). - Seiichi Manyama, May 13 2022

Extensions

New name using e.g.f., Joerg Arndt, Sep 30 2013

A177699 Expansion of e.g.f. log(1+x) * sinh(x).

Original entry on oeis.org

0, 0, 2, -3, 12, -40, 190, -1071, 7224, -56232, 495898, -4880755, 53005700, -629398848, 8110146070, -112690225935, 1679413757168, -26719024870576, 451969255722162, -8099650628337987, 153288815339260796, -3054957193416951480, 63949589015139119598, -1402819397613793354063
Offset: 0

Views

Author

Michel Lagneau, May 11 2010

Keywords

Examples

			log(1+x) * sinh(x) = x^2 -x^3/2 +x^4/2 -x^5/3 +19*x^6/72 -17*x^7/80 +...
		

References

  • L. Comtet and M. Fiolet, Sur les dérivées successives d'une fonction implicite. C. R. Acad. Sci. Paris Ser. A 278 (1974), 249-251.

Crossrefs

Programs

  • Maple
    A177699 := proc(n)
            log(1+x)*sinh(x) ;
            coeftayl(%,x=0,n)*n! ;
    end proc;
    seq(A177699(n),n=0..20) ; # R. J. Mathar, Nov 07 2011
  • Mathematica
    Table[n ((-1)^n HypergeometricPFQ[{1, 1, 1 - n}, {2}, -1] + HypergeometricPFQ[{1, 1, 1 - n}, {2}, 1])/2, {n, 1, 20}] (* Benedict W. J. Irwin, May 30 2016 *)
  • PARI
    a(n) = (-1)^n*sum(k=1, n\2, (n-2*k)!*binomial(n, 2*k-1)); \\ Seiichi Manyama, Feb 12 2025

Formula

a(n) = n*((-1)^n*3F1(1,1,1-n;2;-1)+3F1(1,1,1-n;2;1))/2, n>0. - Benedict W. J. Irwin, May 30 2016
a(n) ~ (-1)^n * (n-1)! * sinh(1). - Vaclav Kotesovec, May 30 2016
a(n) = (-1)^n * Sum_{k=1..floor(n/2)} (n-2*k)! * binomial(n,2*k-1). - Seiichi Manyama, Feb 12 2025

A346395 Expansion of e.g.f. -log(1 - x) * exp(3*x).

Original entry on oeis.org

0, 1, 7, 38, 192, 969, 5115, 29322, 187992, 1370745, 11392839, 107043606, 1122823944, 12989320785, 164040593067, 2243143392138, 32994768719376, 519229765892241, 8701862242296807, 154700700117472422, 2907409255935736752, 57588370882960384377, 1198954118077558162875
Offset: 0

Views

Author

Ilya Gutkovskiy, Jul 15 2021

Keywords

Crossrefs

Programs

  • Mathematica
    nmax = 22; CoefficientList[Series[-Log[1 - x] Exp[3 x], {x, 0, nmax}], x] Range[0, nmax]!
    Table[n! Sum[3^k/((n - k) k!), {k, 0, n - 1}], {n, 0, 22}]
  • PARI
    a_vector(n) = my(v=vector(n+1, i, if(i==2, 1, 0))); for(i=2, n, v[i+1]=(i+2)*v[i]-3*(i-1)*v[i-1]+3^(i-1)); v; \\ Seiichi Manyama, May 27 2022

Formula

a(n) = n! * Sum_{k=0..n-1} 3^k / ((n-k) * k!).
a(n) ~ exp(3) * (n-1)!. - Vaclav Kotesovec, Aug 09 2021
a(0) = 0, a(1) = 1, a(n) = (n+2) * a(n-1) - 3 * (n-1) * a(n-2) + 3^(n-1). - Seiichi Manyama, May 27 2022

A001338 -1 + Sum (k-1)! C(n,k), k = 1..n for n > 0, a(0) = 1.

Original entry on oeis.org

1, 0, 2, 7, 23, 88, 414, 2371, 16071, 125672, 1112082, 10976183, 119481295, 1421542640, 18348340126, 255323504931, 3809950977007, 60683990530224, 1027542662934914, 18430998766219335, 349096664728623335, 6962409983976703336, 145841989688186383358
Offset: 0

Views

Author

Keywords

References

  • N. J. A. Sloane, A Handbook of Integer Sequences, Academic Press, 1973 (includes this sequence).
  • N. J. A. Sloane and Simon Plouffe, The Encyclopedia of Integer Sequences, Academic Press, 1995 (includes this sequence).

Crossrefs

Partial sums of A000522.
Equals A002104(n) + 1.

Programs

  • Mathematica
    Join[{1}, Table[-1 + Sum[(k - 1)! Binomial[n, k], {k, n}], {n, 20}]] (* T. D. Noe, Jun 28 2012 *)

Formula

Conjecture: a(n) +(-n-1)*a(n-1) +2*(n-1)*a(n-2) +(-n+2)*a(n-3)=0. - R. J. Mathar, Feb 16 2014
a(n) = n*a(n-1) - (n-1)*a(n-2) - 1, with a sign reversal for n>=2. - Richard R. Forberg, Dec 16 2014

A260323 Triangle read by rows: T(n,k) = logarithmic polynomial G_k^(n)(x) evaluated at x=-1.

Original entry on oeis.org

1, 3, 2, 8, 6, 6, 24, 24, 24, 24, 89, 80, 60, 120, 120, 415, 450, 480, 360, 720, 720, 2372, 2142, 2730, 840, 2520, 5040, 5040, 16072, 17696, 10416, 21840, 6720, 20160, 40320, 40320, 125673, 112464, 151704, 184464, 15120, 60480, 181440, 362880, 362880
Offset: 1

Views

Author

N. J. A. Sloane, Jul 23 2015

Keywords

Examples

			Triangle begins:
1,
3,2,
8,6,6,
24,24,24,24,
89,80,60,120,120,
415,450,480,360,720,720,
2372,2142,2730,840,2520,5040,5040,
...
		

Crossrefs

Rows, column sums give A002104, A002742, A002745, A002746.

Programs

  • Maple
    A260323 := proc(n,r)
        if r = 0 then
            1 ;
        elif n > r+1 then
            0 ;
        else
            add( 1/(r-j*n)!/j,j=1..(r)/n) ;
            %*r! ;
        end if;
    end proc:
    for r from 1 to 20 do
        for n from 1 to r do
            printf("%a,",A260323(n,r)) ;
        end do:
        printf("\n") ;
    end do: # R. J. Mathar, Jul 24 2015
  • Mathematica
    T[n_, k_] := If[n == 0, 1, If[k > n+1, 0, Sum[1/(n - j*k)!/j, {j, 1, n/k}]]]*n!;
    Table[T[n, k], {n, 1, 10}, {k, 1, n}] // Flatten (* Jean-François Alcover, Jun 25 2023, after R. J. Mathar *)

A346394 Expansion of e.g.f. -log(1 - x) * exp(2*x).

Original entry on oeis.org

0, 1, 5, 20, 78, 324, 1520, 8336, 53872, 405600, 3492416, 33798016, 362543104, 4264455168, 54540715008, 753246711808, 11168972683264, 176937613586432, 2982069587042304, 53271637651996672, 1005385746384846848, 19987620914387812352, 417489079682758213632
Offset: 0

Views

Author

Ilya Gutkovskiy, Jul 15 2021

Keywords

Crossrefs

Programs

  • Mathematica
    nmax = 22; CoefficientList[Series[-Log[1 - x] Exp[2 x], {x, 0, nmax}], x] Range[0, nmax]!
    Table[n! Sum[2^k/((n - k) k!), {k, 0, n - 1}], {n, 0, 22}]
  • PARI
    a_vector(n) = my(v=vector(n+1, i, if(i==2, 1, 0))); for(i=2, n, v[i+1]=(i+1)*v[i]-2*(i-1)*v[i-1]+2^(i-1)); v; \\ Seiichi Manyama, May 27 2022

Formula

a(n) = n! * Sum_{k=0..n-1} 2^k / ((n-k) * k!).
a(n) = Sum_{k=0..n} binomial(n,k) * A002104(k).
a(n) ~ exp(2) * (n-1)!. - Vaclav Kotesovec, Aug 09 2021
a(0) = 0, a(1) = 1, a(n) = (n+1) * a(n-1) - 2 * (n-1) * a(n-2) + 2^(n-1). - Seiichi Manyama, May 27 2022

A346396 Expansion of e.g.f. -log(1 - x) * exp(4*x).

Original entry on oeis.org

0, 1, 9, 62, 390, 2384, 14680, 93680, 635824, 4697664, 38442112, 351331584, 3582715136, 40476303360, 501863078912, 6767130867712, 98464775493632, 1536203429306368, 25564684461735936, 451816479967608832, 8448863295040978944, 166627401783086415872, 3455980532191764676608
Offset: 0

Views

Author

Ilya Gutkovskiy, Jul 15 2021

Keywords

Crossrefs

Programs

  • Mathematica
    nmax = 22; CoefficientList[Series[-Log[1 - x] Exp[4 x], {x, 0, nmax}], x] Range[0, nmax]!
    Table[n! Sum[4^k/((n - k) k!), {k, 0, n - 1}], {n, 0, 22}]
  • PARI
    a_vector(n) = my(v=vector(n+1, i, if(i==2, 1, 0))); for(i=2, n, v[i+1]=(i+3)*v[i]-4*(i-1)*v[i-1]+4^(i-1)); v; \\ Seiichi Manyama, May 27 2022

Formula

a(n) = n! * Sum_{k=0..n-1} 4^k / ((n-k) * k!).
a(n) ~ exp(4) * (n-1)!. - Vaclav Kotesovec, Aug 09 2021
a(0) = 0, a(1) = 1, a(n) = (n+3) * a(n-1) - 4 * (n-1) * a(n-2) + 4^(n-1). - Seiichi Manyama, May 27 2022

A353546 Expansion of e.g.f. -log(1-2*x) * exp(x)/2.

Original entry on oeis.org

0, 1, 4, 17, 96, 729, 7060, 83033, 1146656, 18164625, 324488068, 6450956929, 141233271872, 3376008830505, 87480173354964, 2442396780039817, 73089894980585408, 2333809837398044321, 79198287879591647364, 2846319497398561356913
Offset: 0

Views

Author

Seiichi Manyama, May 27 2022

Keywords

Crossrefs

Cf. A346394.
Essentially partial sums of A010844.

Programs

  • PARI
    my(N=20, x='x+O('x^N)); concat(0, Vec(serlaplace(-log(1-2*x)*exp(x)/2)))
    
  • PARI
    a(n) = n!*sum(k=0, n-1, 2^(n-1-k)/((n-k)*k!));
    
  • PARI
    a_vector(n) = my(v=vector(n+1, i, if(i==2, 1, 0))); for(i=2, n, v[i+1]=(2*i-1)*v[i]-2*(i-1)*v[i-1]+1); v;

Formula

a(n) = n! * Sum_{k=0..n-1} 2^(n-1-k) / ((n-k) * k!).
a(0) = 0, a(1) = 1, a(n) = (2 * n - 1) * a(n-1) - 2 * (n-1) * a(n-2) + 1.
a(n) ~ (n-1)! * exp(1/2) * 2^(n-1). - Vaclav Kotesovec, Jun 08 2022

A353547 Expansion of e.g.f. -log(1-3*x) * exp(x)/3.

Original entry on oeis.org

0, 1, 5, 30, 256, 2969, 43665, 776194, 16159304, 385353945, 10353609253, 309401268494, 10177974023448, 365446593201793, 14220922741157249, 596150920955286402, 26783000840591098288, 1283751796983110068817, 65389160400251577565797
Offset: 0

Views

Author

Seiichi Manyama, May 27 2022

Keywords

Crossrefs

Cf. A346395.
Essentially partial sums of A010845.

Programs

  • PARI
    my(N=20, x='x+O('x^N)); concat(0, Vec(serlaplace(-log(1-3*x)*exp(x)/3)))
    
  • PARI
    a(n) = n!*sum(k=0, n-1, 3^(n-1-k)/((n-k)*k!));
    
  • PARI
    a_vector(n) = my(v=vector(n+1, i, if(i==2, 1, 0))); for(i=2, n, v[i+1]=(3*i-2)*v[i]-3*(i-1)*v[i-1]+1); v;

Formula

a(n) = n! * Sum_{k=0..n-1} 3^(n-1-k) / ((n-k) * k!).
a(0) = 0, a(1) = 1, a(n) = (3 * n - 2) * a(n-1) - 3 * (n-1) * a(n-2) + 1.
a(n) ~ (n-1)! * exp(1/3) * 3^(n-1). - Vaclav Kotesovec, Jun 08 2022
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