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 1-4 of 4 results.

A248871 Coefficients in asymptotic expansion of sequence A107895.

Original entry on oeis.org

1, 1, 3, 12, 66, 450, 3679, 35260, 388511, 4844584, 67502450, 1039929756, 17556193609, 322321551868, 6393505020803, 136245752898586, 3103879644045050, 75268872986970840, 1935571325829192247, 52605265683008056660, 1506530437404419817467
Offset: 0

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Author

Vaclav Kotesovec, Mar 14 2015

Keywords

Examples

			A107895(n) / n! ~ 1 + 1/n + 3/n^2 + 12/n^3 + 66/n^4 + 450/n^5 + 3679/n^6 + ...
		

Crossrefs

Formula

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

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

Views

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)).

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

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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

A256126 Coefficients in asymptotic expansion of sequence A179327.

Original entry on oeis.org

1, 1, 3, 11, 50, 278, 1860, 14793, 138166, 1494034, 18422609, 255359957, 3929301362, 66412322717, 1222216175058, 24314268876147, 519701698551031, 11874016816562299, 288722141589331161, 7442890569982739838, 202733505298293899570, 5817564888930184685708
Offset: 0

Views

Author

Vaclav Kotesovec, Mar 15 2015

Keywords

Examples

			A179327(n) / (n-1)! ~ 1 + 1/n + 3/n^2 + 11/n^3 + 50/n^4 + 278/n^5 + 1860/n^6 + ...
		

Crossrefs

Formula

a(k) ~ (k-1)! / (log(2))^k.
Showing 1-4 of 4 results.