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 1-3 of 3 results.

A058699 a(n) = p(p(n)), p = partition numbers A000041.

Original entry on oeis.org

1, 1, 2, 3, 7, 15, 56, 176, 1002, 5604, 53174, 526823, 10619863, 214481126, 9035836076, 476715857290, 51820051838712, 7479565078510584, 2645418340688763701, 1318520401612270233223, 1774758704783877366657989, 4025091510519029370421431033
Offset: 0

Views

Author

N. J. A. Sloane, Dec 31 2000

Keywords

Links

Crossrefs

Cf. A000009, A000041, A284908, A284909, A284910.

Programs

  • Maple
    a:= n-> (combinat[numbpart]@@2)(n):
seq(a(n), n=0..22);  # Alois P. Heinz, Apr 05 2017
  • Mathematica
    Table[Nest[PartitionsP, n, 2], {n, 0, 20}] (* Michael De Vlieger, Apr 25 2016 *)
  • PARI
    a(n) = numbpart(numbpart(n)); \\ Michel Marcus, Apr 25 2016

Formula

a(n) = A000041(A000041(n)). - Omar E. Pol, Apr 25 2016

A284908 a(n) = A000009(A000009(n)).

Original entry on oeis.org

1, 1, 1, 1, 1, 2, 2, 3, 4, 6, 10, 15, 27, 46, 89, 192, 390, 864, 2304, 5718, 16444, 53250, 173682, 618784, 2556284, 11086968, 53466624, 299016608, 1780751883, 11784471548, 94036004868, 795888123110, 7723778471936, 91117574462854, 1168225267521350
Offset: 0

Views

Author

Alois P. Heinz, Apr 05 2017

Keywords

Links

Crossrefs

Cf. A000009, A000041, A058699, A284909, A284910.

Programs

  • Maple
    with(numtheory):
b:= proc(n) option remember; `if`(n=0, 1, add(add(
      `if`(d::odd, d, 0), d=divisors(j))*b(n-j), j=1..n)/n)
    end:
a:= n-> b(b(n)):
seq(a(n), n=0..35);
  • Mathematica
    Table[PartitionsQ@ PartitionsQ@ n, {n, 0, 50}] (* Indranil Ghosh, Apr 07 2017 *)

A284909 a(n) = A000041(A000009(n)).

Original entry on oeis.org

1, 1, 1, 2, 2, 3, 5, 7, 11, 22, 42, 77, 176, 385, 1002, 3010, 8349, 26015, 105558, 386155, 1741630, 9289091, 49995925, 304801365, 2291320912, 18440293320, 172389800255, 1987276856363, 25025873760111, 365749566870782, 6965850144195831, 144117936527873832
Offset: 0

Views

Author

Alois P. Heinz, Apr 05 2017

Keywords

Links

Crossrefs

Cf. A000009, A000041, A058699, A284908, A284910.

Programs

  • Maple
    with(numtheory):
b:= proc(n) option remember; `if`(n=0, 1, add(add(
     `if`(d::odd, d, 0), d=divisors(j))*b(n-j), j=1..n)/n)
    end:
a:= n-> combinat[numbpart](b(n)):
seq(a(n), n=0..35);
  • Mathematica
    Table[PartitionsP@ PartitionsQ@ n, {n,0, 50}] (* Indranil Ghosh, Apr 07 2017 *)
Showing 1-3 of 3 results.

Started in 1964 by Neil J. A. Sloane | Maintained by The OEIS Foundation Inc.

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