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.

A248518 Number of partitions of n into parts > 0 without 1 as digit, cf. A052383.

Original entry on oeis.org

1, 0, 1, 1, 2, 2, 4, 4, 7, 8, 11, 13, 19, 21, 29, 34, 44, 51, 66, 75, 96, 110, 136, 157, 193, 220, 267, 307, 367, 421, 501, 571, 677, 772, 905, 1033, 1207, 1371, 1595, 1812, 2096, 2377, 2741, 3101, 3564, 4028, 4608, 5203, 5938, 6688, 7612, 8564, 9719, 10919
Offset: 0

Views

Author

Reinhard Zumkeller, Oct 07 2014

Keywords

Comments

Note that the definition says "1 as a DIGIT", not "1 as a PART". - N. J. A. Sloane, Jun 28 2017

Examples

			The full list of partitions of 10 is as follows:
[[1, 1, 1, 1, 1, 1, 1, 1, 1, 1], [1, 1, 1, 1, 1, 1, 1, 1, 2],
    [1, 1, 1, 1, 1, 1, 2, 2], [1, 1, 1, 1, 2, 2, 2], [1, 1, 2, 2, 2, 2],
    [2, 2, 2, 2, 2], [1, 1, 1, 1, 1, 1, 1, 3], [1, 1, 1, 1, 1, 2, 3],
    [1, 1, 1, 2, 2, 3], [1, 2, 2, 2, 3], [1, 1, 1, 1, 3, 3], [1, 1, 2, 3, 3],
    [2, 2, 3, 3], [1, 3, 3, 3], [1, 1, 1, 1, 1, 1, 4], [1, 1, 1, 1, 2, 4],
    [1, 1, 2, 2, 4], [2, 2, 2, 4], [1, 1, 1, 3, 4], [1, 2, 3, 4], [3, 3, 4],
    [1, 1, 4, 4], [2, 4, 4], [1, 1, 1, 1, 1, 5], [1, 1, 1, 2, 5], [1, 2, 2, 5],
    [1, 1, 3, 5], [2, 3, 5], [1, 4, 5], [5, 5], [1, 1, 1, 1, 6], [1, 1, 2, 6],
    [2, 2, 6], [1, 3, 6], [4, 6], [1, 1, 1, 7], [1, 2, 7], [3, 7], [1, 1, 8],
    [2, 8], [1, 9], [10]]
If we excluse those that have a 1 in one of the parts, 11 partitions are left:
[[2, 2, 2, 2, 2], [2, 2, 3, 3], [2, 2, 2, 4], [3, 3, 4], [2, 4, 4], [2, 3, 5], [5, 5], [2, 2, 6], [4, 6], [3, 7], [2, 8]].
So a(10) = 11. - _N. J. A. Sloane_, Jun 28 2017
a(11) = #{9+2, 8+3, 7+4, 7+2+2, 6+5, 6+3+2, 5+4+2, 5+3+3, 5+2+2+2, 4+4+3, 4+3+2+2, 3+3+3+2, 3+2+2+2+2} = 13;
a(12) = #{9+3, 8+4, 8+2+2, 7+5, 7+3+2, 6+6, 6+4+2, 6+3+3, 6+2+2+2, 5+5+2, 5+4+3, 5+3+2+2, 4+4+4, 4+4+2+2, 4+3+3+2, 4+2+2+2+2, 3+3+3+3, 3+3+2+2+2, 6x2} = 19.
		

Crossrefs

Programs

  • Haskell
    a248518 = p $ tail a052383_list where
       p _          0 = 1
       p ks'@(k:ks) m = if m < k then 0 else p ks' (m - k) + p ks m
  • Mathematica
    Table[Length[Select[IntegerPartitions[n],!MemberQ[Flatten[ IntegerDigits/@#],1]&]],{n,0,60}] (* Harvey P. Dale, Jun 28 2017 *)