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.

A096066 Triangle read by rows, 1<=k<=n: T(n,k) is the number of occurrences of the k-th prime in partitions of the n-th prime into primes.

Original entry on oeis.org

1, 0, 1, 1, 1, 1, 3, 1, 1, 1, 10, 6, 2, 1, 1, 16, 9, 4, 2, 1, 1, 37, 22, 11, 6, 2, 1, 1, 54, 32, 15, 9, 3, 2, 1, 1, 107, 65, 32, 19, 7, 5, 2, 1, 1, 266, 165, 84, 50, 22, 15, 7, 5, 2, 1, 353, 219, 112, 69, 30, 21, 10, 7, 3, 1, 1, 779, 487, 254, 157, 73, 52, 27, 19, 10, 3, 2, 1, 1270, 795, 420, 261, 124, 90, 49, 36, 19, 7, 5, 1, 1
Offset: 1

Views

Author

Reinhard Zumkeller, Jul 21 2004

Keywords

Examples

			n=5, A000040(5)=11 with A056768(5)=6 partitions into primes:
T(5,1)=10 prime(1)=2 in 7+2+2=5+2+2+2=3+3+3+2=3+2+2+2+2,
T(5,2)=6 prime(2)=3: in 5+3+3=3+3+3+2=3+2+2+2+2,
T(5,3)=2 prime(3)=5: in 5+3+3=5+2+2+2,
T(5,4)=1 prime(4)=7: in 7+2+2.
Triangle begins:
  1;
  0,  1;
  1,  1, 1;
  3,  1, 1, 1;
  10, 6, 2, 1, 1;
  ...
		

Crossrefs

Cf. A056768.

Programs

  • Mathematica
    ip[p_] := ip[p] = IntegerPartitions[p, All, Select[Range[p], PrimeQ]] // Flatten;
    T[n_, k_] := Count[ip[Prime[n]], Prime[k]];
    Table[T[n, k], {n, 1, 13}, {k, 1, n}] // Flatten (* Jean-François Alcover, Sep 23 2021 *)

Formula

T(n,n) = 1.

Extensions

Name modified by Jean-François Alcover, Sep 23 2021