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.

Showing 1-10 of 16 results. Next

A256125 Coefficients in asymptotic expansion of sequence A077365.

Original entry on oeis.org

1, 1, 3, 12, 67, 457, 3734, 35741, 392875, 4886114, 67924417, 1044531625, 17609980356, 322993544751, 6402464186243, 136373115537072, 3105809328600351, 75300018326324541, 1936106590359322126, 52615058519875702993, 1506721174739412743551
Offset: 0

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Author

Vaclav Kotesovec, Mar 15 2015

Keywords

Examples

			A077365(n) / n! ~ 1 + 1/n + 3/n^2 + 12/n^3 + 67/n^4 + 457/n^5 + 3734/n^6 + ...
		

Crossrefs

Formula

a(k) ~ k! / (4 * (log(2))^(k+1)).

A107895 Euler transform of n!.

Original entry on oeis.org

1, 1, 3, 9, 36, 168, 961, 6403, 49302, 430190, 4199279, 45326013, 535867338, 6884000262, 95453970483, 1420538043009, 22579098396600, 381704267100888, 6837775526561031, 129377310771795789, 2578101967764973314, 53965231260126083854, 1183813954026245944519
Offset: 0

Views

Author

Thomas Wieder, May 26 2005

Keywords

Crossrefs

Programs

  • Maple
    EulerTrans := proc(p) local b; b := proc(n) option remember; local d, j;
    `if`(n=0,1, add(add(d*p(d),d=numtheory[divisors](j)) *b(n-j),j=1..n)/n) end end:
    A107895 := EulerTrans(n->n!):  seq(A107895(n),n=0..20);
    # After Alois P. Heinz, A000335.  [Peter Luschny, Jul 07 2011]
  • Mathematica
    EulerTrans[p_] := Module[{b}, b[n_] := b[n] = Module[{d, j}, If[n == 0, 1, Sum[Sum[d*p[d], {d, Divisors[j]}]*b[n-j], {j, 1, n}]/n]]; b]; A107895 = EulerTrans[Factorial]; Table[A107895[n], {n, 0, 22}] (* Jean-François Alcover, Feb 25 2014, after Alois P. Heinz *)

Formula

a(n) ~ n! * (1 + 1/n + 3/n^2 + 12/n^3 + 66/n^4 + 450/n^5 + 3679/n^6 + 35260/n^7 + 388511/n^8 + 4844584/n^9 + 67502450/n^10), for next coefficients see A248871. - Vaclav Kotesovec, Mar 14 2015
G.f.: Product_{n>=1} 1/(1-x^n)^(n!). - Vaclav Kotesovec, Aug 04 2015

A265950 Expansion of Product_{k>=1} (1 + k!*x^k).

Original entry on oeis.org

1, 1, 2, 8, 30, 156, 900, 6192, 47904, 422928, 4138848, 44864640, 531227520, 6836927040, 94891046400, 1413494219520, 22481104677120, 380261238681600, 6814832064422400, 128991143627965440, 2571187988206540800, 53834676521793638400, 1181214133296983654400
Offset: 0

Views

Author

Vaclav Kotesovec, Dec 19 2015

Keywords

Crossrefs

Programs

  • Mathematica
    nmax=30; CoefficientList[Series[Product[(1+k!*x^k), {k, 1, nmax}], {x, 0, nmax}], x]

Formula

a(n) ~ n! * (1 + 1/n + 2/n^2 + 10/n^3 + 56/n^4 + 394/n^5 + 3332/n^6 + 32782/n^7 + 368072/n^8 + 4651666/n^9 + 65440748/n^10 + ...), for coefficients see A265954.
G.f.: exp(Sum_{k>=1} Sum_{j>=1} (-1)^(k+1)*(j!)^k*x^(j*k)/k). - Ilya Gutkovskiy, Jun 18 2018

A134134 Triangle of numbers obtained from the partition array A134133.

Original entry on oeis.org

1, 2, 1, 6, 2, 1, 24, 10, 2, 1, 120, 36, 10, 2, 1, 720, 204, 44, 10, 2, 1, 5040, 1104, 228, 44, 10, 2, 1, 40320, 7776, 1272, 244, 44, 10, 2, 1, 362880, 57600, 8760, 1320, 244, 44, 10, 2, 1, 3628800, 505440, 63936, 9096, 1352, 244, 44, 10, 2, 1
Offset: 1

Views

Author

Wolfdieter Lang, Oct 12 2007

Keywords

Comments

In the same manner the unsigned Lah triangle A008297 is obtained from the partition array A130561.

Examples

			[1];[2,1];[6,2,1];[24,10,2,1];[120,36,10,2,1];...
a(4,2)=10 from the sum over the numbers related to the partitions (1,3) and (2^2), namely
1!^1*3!^1 + 2!^2 = 6+4 = 10.
		

Crossrefs

Row sums A077365. Alternating row sums A134135.

Formula

a(n,m)=sum(product(j!^e(n,m,k,j),j=1..n),k=1..p(n,m)) if n>=m>=1, else 0, with p(n,m)=A008284(n,m), the number of m parts partitions of n and e(n,m,k,j) is the exponent of j in the k-th m part partition of n.

A107107 For each partition of n, calculate (dM2/dM3) where dM2 = A036039(p) and dM3 = A036040(p); then sum over all partitions of n.

Original entry on oeis.org

1, 1, 2, 4, 11, 37, 168, 926, 6181, 47651, 418546, 4106264, 44537519, 528408261, 6807428748, 94588717554, 1409927483625, 22437711255279, 379674820846534, 6806486383431340, 128862216628864163, 2569080120361323721, 53797824318887051264, 1180533584545138213222
Offset: 0

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Author

Alford Arnold, May 12 2005

Keywords

Comments

Values for individual partitions (A107106) are factorials when all but one part of the partition has size one or two, but not usually in other cases.

Examples

			For n = 6, (120,144,90,40,90,120,15,40,45,15,1) / (1,6,15,10,15,60,15,20,45,15,1)
  equals (120,24,6,4,6,2,1,2,1,1,1) so A107107(6) = 168.
		

Crossrefs

Programs

  • Maple
    b:= proc(n, i) option remember;
          `if`(n=0, 1, `if`(i<1, 0, b(n, i-1)+
          `if`(i>n, 0, b(n-i, i)*(i-1)!)))
        end:
    a:= n-> b(n$2):
    seq(a(n), n=0..30);  # Alois P. Heinz, May 11 2016
  • Mathematica
    nmax=20; CoefficientList[Series[Product[1/(1-(k-1)!*x^k),{k,1,nmax}],{x,0,nmax}],x] (* Vaclav Kotesovec, Mar 15 2015 *)
  • Maxima
    S(n,m):=if n=0 then 1 else if nVladimir Kruchinin, Sep 07 2014 */

Formula

For partition [], the contribution to the sum is product_i (c_i - 1)!^k_i.
G.f.: 1/Product_{m>0} (1-(m-1)!*x^m). - Vladeta Jovovic, Jul 10 2007
a(n) = S(n,1), where S(n,m) = sum(k=m..n/2, (k-1)!*S(n-k,k))+(n-1)!, S(n,n)=(n-1)!, S(0,m)=1, S(n,m)=0 for m>n. - Vladimir Kruchinin, Sep 07 2014
a(n) ~ (n-1)! * (1 + 1/n + 3/n^2 + 11/n^3 + 50/n^4 + 278/n^5 + 1861/n^6 + 14815/n^7 + 138477/n^8 + 1497775/n^9 + 18465330/n^10). - Vaclav Kotesovec, Mar 15 2015

Extensions

Edited, corrected and extended by Franklin T. Adams-Watters, Nov 03 2005
More terms from Vladeta Jovovic, Jul 10 2007

A300520 Expansion of Product_{k>=1} 1 / (1 - Fibonacci(k)*x^k).

Original entry on oeis.org

1, 1, 2, 4, 8, 15, 31, 57, 113, 212, 410, 757, 1464, 2684, 5083, 9380, 17569, 32120, 59977, 109193, 202046, 367951, 675541, 1224453, 2243795, 4052369, 7377243, 13314989, 24140198, 43406515, 78510429, 140800279, 253663615, 454352111, 815790813, 1457485309
Offset: 0

Views

Author

Vaclav Kotesovec, Mar 08 2018

Keywords

Crossrefs

Programs

  • Mathematica
    nmax = 40; CoefficientList[Series[Product[1/(1-Fibonacci[k]*x^k), {k, 1, nmax}], {x, 0, nmax}], x]

Formula

log(a(n)) ~ log(phi)*n + 2*sqrt(polylog(2, 1/sqrt(5))*n) - 3*(log(n)/4), where polylog(2, 1/sqrt(5)) = 0.5107013915606224266804289751265205446721... and phi = A001622 = (1 + sqrt(5))/2 is the golden ratio.

A107894 Sum over the products of factorials of parts in all partitions of n where the sum runs over the number of different parts only.

Original entry on oeis.org

1, 1, 3, 9, 35, 167, 943, 6379, 48945, 429651, 4189865, 45307601, 535518109, 6883110373, 95435065935, 1420468921893, 22577620176887, 381695573051099, 6837601709298811, 129375694813679215, 2578070946813526485, 53964818587883937807, 1183805926540690127573
Offset: 0

Views

Author

Thomas Wieder, May 26 2005

Keywords

Examples

			The partitions of 5 are 1+1+1+1+1, 1+1+1+2, 1+1+3, 1+2+2, 1+4, 2+3, 5, the corresponding products of factorials of parts are (when multiple parts are counted once only) 1!, 1!*2!, 1!*3!, 1!*2!, 1!*4!, 2!*3!, 5! and their sum is a(5) = 167.
		

Crossrefs

Programs

  • Maple
    b:= proc(n, i) option remember;
          `if`(n=0 or i<2, 1, b(n, i-1) +i!*add(b(n-i*j, i-1), j=1..n/i))
        end:
    a:= n-> b(n, n):
    seq(a(n), n=0..30); # Alois P. Heinz, Apr 04 2012
  • Mathematica
    Total[Times@@@(Union/@IntegerPartitions[#]!)]&/@Range[20]  (* Harvey P. Dale, Feb 26 2011 *)
    b[n_, i_] := b[n, i] = If[n==0 || i<2, 1, b[n, i-1] + i!*Sum[b[n-i*j, i-1], {j, 1, n/i}]]; a[n_] := b[n, n]; Table[a[n], {n, 0, 30}] (* Jean-François Alcover, Oct 29 2015, after Alois P. Heinz *)

Formula

a(n) ~ n! * (1 + 1/n + 3/n^2 + 12/n^3 + 65/n^4 + 443/n^5 + 3626/n^6 + 34811/n^7 + 384479/n^8 + 4806098/n^9 + 67109281/n^10), for coefficients see A256124. - Vaclav Kotesovec, Mar 15 2015

Extensions

a(0) inserted and more terms from Alois P. Heinz, Apr 04 2012

A265954 Coefficients in asymptotic expansion of sequence A265950.

Original entry on oeis.org

1, 1, 2, 10, 56, 394, 3332, 32782, 368072, 4651666, 65440748, 1015205974, 17225810768, 317432262298, 6313880504564, 134828046043486, 3076458785723864, 74696205255843490, 1922729345267645180, 52297599798809376358, 1498690940537194229600
Offset: 0

Views

Author

Vaclav Kotesovec, Dec 19 2015

Keywords

Examples

			A265950(n) / n! ~ 1 + 1/n + 2/n^2 + 10/n^3 + 56/n^4 + 394/n^5 + 3332/n^6 + ...
		

Crossrefs

Formula

a(k) ~ k! / (4 * (log(2))^(k+1)).

A292279 Expansion of 1/Product_{k>=1} (1 + k!*x^k).

Original entry on oeis.org

1, -1, -1, -5, -15, -93, -551, -4129, -33607, -312929, -3179343, -35602881, -432201743, -5678740945, -80142780751, -1210609725905, -19481112885231, -332836223507793, -6016678424942063, -114746996449871761, -2302527084416470255, -48495552665272893329
Offset: 0

Views

Author

Seiichi Manyama, Sep 13 2017

Keywords

Crossrefs

Programs

  • Mathematica
    nmax = 25; CoefficientList[Series[Product[1/(1 + k!*x^k), {k, 1, nmax}], {x, 0, nmax}], x] (* Vaclav Kotesovec, Sep 13 2017 *)
  • PARI
    {a(n) = polcoeff(1/prod(k=1, n, 1+k!*x^k+x*O(x^n)), n)}

Formula

Convolution inverse of A265950.
a(n) ~ -n! * (1 - 1/n - 1/n^2 - 6/n^3 - 31/n^4 - 219/n^5 - 1932/n^6 - 19945/n^7 - 234837/n^8 - 3104108/n^9 - 45495817/n^10). - Vaclav Kotesovec, Sep 14 2017
G.f.: exp(Sum_{k>=1} Sum_{j>=1} (-1)^k*(j!)^k*x^(j*k)/k). - Ilya Gutkovskiy, Jun 18 2018

A292280 Expansion of Product_{k>=1} (1 - k!*x^k).

Original entry on oeis.org

1, -1, -2, -4, -18, -84, -564, -3984, -33504, -307728, -3156192, -35254080, -429350400, -5641133760, -79720588800, -1204747741440, -19400679325440, -331599765565440, -5996988417784320, -114408970262922240, -2296442484579686400, -48379417944213196800
Offset: 0

Views

Author

Seiichi Manyama, Sep 13 2017

Keywords

Crossrefs

Programs

  • Mathematica
    nmax = 25; CoefficientList[Series[Product[(1 - k!*x^k), {k, 1, nmax}], {x, 0, nmax}], x] (* Vaclav Kotesovec, Sep 13 2017 *)
  • PARI
    {a(n) = polcoeff(prod(k=1, n, 1-k!*x^k+x*O(x^n)), n)}

Formula

Convolution inverse of A077365.
a(n) ~ -n! * (1 - 1/n - 2/n^2 - 6/n^3 - 32/n^4 - 222/n^5 - 1916/n^6 - 19650/n^7 - 231200/n^8 - 3058566/n^9 - 44883428/n^10). - Vaclav Kotesovec, Sep 14 2017
G.f.: exp(-Sum_{k>=1} Sum_{j>=1} (j!)^k*x^(j*k)/k). - Ilya Gutkovskiy, Jun 18 2018
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