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 1-2 of 2 results.

A090011 T(n,k) = number of partitions of binomial(n,k), 0<=k<=n, triangular array read by rows.

Original entry on oeis.org

1, 1, 1, 1, 2, 1, 1, 3, 3, 1, 1, 5, 11, 5, 1, 1, 7, 42, 42, 7, 1, 1, 11, 176, 627, 176, 11, 1, 1, 15, 792, 14883, 14883, 792, 15, 1, 1, 22, 3718, 526823, 4087968, 526823, 3718, 22, 1, 1, 30, 17977, 26543660, 3519222692, 3519222692, 26543660, 17977, 30, 1, 1, 42, 89134
Offset: 0

Views

Author

Reinhard Zumkeller, Jan 28 2004

Keywords

Comments

a(n) = A000041(A007318(n));
T(n,0) = T(n,n) = 1; T(n,1) = T(n,n-1) = A000041(n), n>0.

Examples

			Triangle begins:
1;
1, 1;
1, 2, 1;
1, 3, 3, 1;
1, 5, 11, 5, 1;
1, 7, 42, 42, 7, 1;
1, 11, 176, 627, 176, 11, 1;
1, 15, 792, 14883, 14883, 792, 15, 1;
1, 22, 3718, 526823, 4087968, 526823, 3718, 22, 1;
1, 30, 17977, 26543660, 3519222692, 3519222692, 26543660, 17977, 30, 1;
1, 42, 89134, 1844349560, 9275102575355, 269232701252579, 9275102575355, 1844349560, 89134, 42, 1; ...
		

Crossrefs

Cf. A226659 (row sums), A128855 (central terms).

Programs

  • Mathematica
    Flatten[Table[PartitionsP[Binomial[n,k]],{n,0,10},{k,0,n}]] (* Indranil Ghosh, Feb 21 2017 *)
  • PARI
    T(n,k)=numbpart(binomial(n,k))
    for(n=0,10,for(k=0,n,print1(T(n,k),", "));print()) \\ Paul D. Hanna, Jun 14 2013

Extensions

Data section corrected by Indranil Ghosh, Feb 21 2017

A226659 Sum_{k=0..n} A000041( binomial(n,k) ), where A000041(n) is the number of partitions of n.

Original entry on oeis.org

1, 2, 4, 8, 23, 100, 1003, 31382, 5149096, 7091568720, 287786595280763, 539018517346414192796, 1130813038175196801809538188145, 2336855300714703790840987155549462486654700, 7636154577344556445476348286247799105605643795614728449082014
Offset: 0

Views

Author

Paul D. Hanna, Jun 14 2013

Keywords

Comments

Compare to the number of partitions of 2^n (A068413).

Examples

			Equals the row sums of triangle A090011, which begins:
1;
1, 1;
1, 2, 1;
1, 3, 3, 1;
1, 5, 11, 5, 1;
1, 7, 42, 42, 7, 1;
1, 11, 176, 627, 176, 11, 1;
1, 15, 792, 14883, 14883, 792, 15, 1;
1, 22, 3718, 526823, 4087968, 526823, 3718, 22, 1; ...
		

Crossrefs

Programs

  • Mathematica
    Table[Sum[PartitionsP[Binomial[n,k]],{k,0,n}],{n,0,20}] (* Indranil Ghosh, Feb 21 2017 *)
  • PARI
    {a(n)=sum(k=0,n,numbpart(binomial(n,k)))}
    for(n=0,15,print1(a(n),", "))

Formula

Row sums of triangle A090011.
Showing 1-2 of 2 results.