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 1-5 of 5 results.

A293266 Coefficients in asymptotic expansion of sequence A096161 and A161779.

Original entry on oeis.org

1, 0, 1, 2, 7, 28, 121, 587, 3205, 19201, 123684, 850873, 6248839, 48948805, 407666212, 3594074850, 33405529547, 326310068618, 3342124657507, 35827145094057, 401325346421766, 4689964771177970, 57081316456694665, 722295766109273335, 9486188532177356598
Offset: 0

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Author

Vaclav Kotesovec, Oct 04 2017

Keywords

Examples

			A096161(n) / n! ~ 1 + 1/n^2 + 2/n^3 + 7/n^4 + 28/n^5 + 121/n^6 + ...
A161779(n) / n! ~ 1 + 1/n^2 + 2/n^3 + 7/n^4 + 28/n^5 + 121/n^6 + ...
		

Crossrefs

A293202 Square array A(n,k), n >= 0, k >= 0, read by antidiagonals, where column k is the expansion of g.f. Product_{i>0} Sum_{j=0..k} j!*x^(j*i).

Original entry on oeis.org

1, 1, 0, 1, 1, 0, 1, 1, 1, 0, 1, 1, 3, 2, 0, 1, 1, 3, 2, 2, 0, 1, 1, 3, 8, 6, 3, 0, 1, 1, 3, 8, 6, 7, 4, 0, 1, 1, 3, 8, 30, 13, 12, 5, 0, 1, 1, 3, 8, 30, 13, 24, 13, 6, 0, 1, 1, 3, 8, 30, 133, 48, 37, 22, 8, 0, 1, 1, 3, 8, 30, 133, 48, 61, 46, 26, 10, 0, 1, 1, 3, 8, 30, 133, 768, 181, 142, 98, 42, 12, 0
Offset: 0

Views

Author

Seiichi Manyama, Oct 02 2017

Keywords

Examples

			Square array begins:
   1, 1, 1,  1,  1, ...
   0, 1, 1,  1,  1, ...
   0, 1, 3,  3,  3, ...
   0, 2, 2,  8,  8, ...
   0, 2, 6,  6, 30, ...
   0, 3, 7, 13, 13, ...
		

Crossrefs

Columns k=0..5 give A000007, A000009, A293204, A289485, A289486, A293250.
Rows n=0..1 give A000012, A057427.
Main diagonal gives A161779.

Programs

  • Maple
    b:= proc(n, i, k) option remember; `if`(n=0, 1, `if`(i<1, 0,
          add(b(n-i*j, i-1, k)*j!, j=0..min(k, n/i))))
        end:
    A:= (n, k)-> b(n$2, k):
    seq(seq(A(n, d-n), n=0..d), d=0..12);  # Alois P. Heinz, Oct 02 2017
  • Mathematica
    b[n_, i_, k_] := b[n, i, k] = If[n == 0, 1, If[i < 1, 0, Sum[b[n - i j, i - 1, k] j!, {j, 0, Min[k, n/i]}]]];
    A [n_, k_] := b[n, n, k];
    Table[Table[A[n, d-n], {n, 0, d}], {d, 0, 12}] // Flatten (* Jean-François Alcover, Dec 06 2019, after Alois P. Heinz *)

A293251 G.f.: Product_{i>0} 1/(Sum_{j>=0} j!*x^(j*i)).

Original entry on oeis.org

1, -1, -2, -3, -13, -65, -447, -3351, -28544, -269270, -2795872, -31689198, -389581679, -5165672203, -73512910689, -1117937393138, -18096787251877, -310743077434399, -5642249024063207, -108023468997424550, -2175086628366359447, -45952007357795606912
Offset: 0

Views

Author

Seiichi Manyama, Oct 04 2017

Keywords

Crossrefs

Programs

  • Mathematica
    nmax = 30; CoefficientList[Series[Product[1/Sum[j!*x^(j*k), {j, 0, nmax}], {k, 1, nmax}], {x, 0, nmax}], x] (* Vaclav Kotesovec, Oct 04 2017 *)

Formula

Convolution inverse of A161779.
a(n) ~ -n! * (1 - 2/n - 2/n^2 - 5/n^3 - 29/n^4 - 232/n^5 - 2231/n^6 - 24745/n^7 - 308917/n^8 - 4279945/n^9 - 65179552/n^10), for coefficients see A293264. - Vaclav Kotesovec, Oct 04 2017

A333144 Irregular triangle where row n lists the product of the factorials of the exponentials of the partitions of n and the partitions are enumerated in canonical order.

Original entry on oeis.org

1, 1, 1, 2, 1, 1, 6, 1, 1, 2, 2, 24, 1, 1, 1, 2, 2, 6, 120, 1, 1, 1, 2, 2, 1, 6, 6, 4, 24, 720, 1, 1, 1, 2, 1, 1, 6, 2, 2, 2, 24, 6, 12, 120, 5040, 1, 1, 1, 2, 1, 1, 6, 2, 1, 2, 2, 24, 2, 4, 2, 6, 120, 24, 12, 48, 720, 40320
Offset: 0

Views

Author

Peter Luschny, Apr 10 2020

Keywords

Comments

By 'canonical order' we understand the graded reverse lexicographic order (the default order of Mathematica and SageMath).

Examples

			The irregular table starts:
[0] [1]
[1] [1]
[2] [1, 2]
[3] [1, 1, 6]
[4] [1, 1, 2, 2, 24]
[5] [1, 1, 1, 2, 2, 6, 120]
[6] [1, 1, 1, 2, 2, 1, 6, 6, 4, 24, 720]
[7] [1, 1, 1, 2, 1, 1, 6, 2, 2, 2, 24, 6, 12, 120, 5040]
		

Crossrefs

Row sums are A161779.
Cf. A069123.

Programs

  • SageMath
    def A333144row(n):
        return [product(factorial(expo) for expo in partition.to_exp()) for partition in Partitions(n)]
    for n in (0..9): print(A333144row(n))

A161993 A006005 (shifted) convolved with all of its regularly "aerated" variants.

Original entry on oeis.org

1, 3, 8, 19, 43, 85, 171, 315, 580, 1022, 1766, 2982, 4959, 8081, 12997, 20596, 32261, 49909, 76447, 115872, 174133, 259312, 383206, 561877, 818225, 1183266, 1700658, 2429266, 3450562, 4874167, 6850072, 9578548, 13331445, 18469783, 25478494, 34999375, 47887091
Offset: 0

Views

Author

Gary W. Adamson, Jun 24 2009

Keywords

Comments

Refer to A161779 for the analogous sequence based on the factorials.
Given A006005 (1 together with the odd primes = odd noncomposite numbers) = a, then b = the aerated variant: (1, 0, 3, 0, 5, 0, 7,...); c = (1, 0, 0, 3, 0, 0, 5,...) and so on such that A161993 = the infinite convolution product: a*b*c*...

Crossrefs

Programs

  • Maple
    p:= n-> `if`(n=0, 1, ithprime(n+1)):
    b:= proc(n, i) option remember; `if`(i>n, 0,
         `if`(irem(n, i, 'r')=0, p(r), 0)+
          add(p(j)*b(n-i*j, i+1), j=0..n/i))
        end:
    a:= n-> `if`(n=0, 1, b(n, 1)):
    seq(a(n), n=0..45);  # Alois P. Heinz, Jul 27 2019
  • Mathematica
    p[n_] := If[n==0, 1, Prime[n+1]];
    b[n_, i_] := b[n, i] = If[i>n, 0, If[Mod[n, i]==0, p[n/i], 0] + Sum[p[j] b[n - i j, i+1], {j, 0, n/i}]];
    a[n_] := If[n==0, 1, b[n, 1]];
    a /@ Range[0, 45] (* Jean-François Alcover, Nov 20 2020, after Alois P. Heinz *)

Extensions

Definition and comment corrected by Omar E. Pol, Aug 18 2011
Correct offset and a(13)-a(36) from Alois P. Heinz, Jul 27 2019
Showing 1-5 of 5 results.