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.

A061827 Number of partitions of n into parts which are the digits of n.

Original entry on oeis.org

1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 7, 5, 4, 4, 3, 3, 3, 3, 1, 11, 1, 4, 7, 3, 5, 2, 4, 2, 1, 11, 6, 1, 3, 3, 7, 2, 2, 5, 1, 11, 11, 4, 1, 3, 4, 2, 7, 2, 1, 11, 6, 4, 3, 1, 2, 2, 2, 2, 1, 11, 11, 11, 6, 3, 1, 2, 3, 4, 1, 11, 6, 4, 3, 3, 2, 1, 2, 2, 1, 11, 11, 4, 11, 3, 4, 2, 1, 2, 1, 11, 6, 11, 3, 3, 6, 2, 2
Offset: 1

Views

Author

Amarnath Murthy, May 28 2001

Keywords

Comments

a(A125289(n)) = 1, a(A125290(n)) > 1.

Examples

			For n = 11, 1+1+1+1+1+1+1+1+1+1+1. so a(11) = 1. For n = 12, 2+2+2+2+2+2 = 2+2+1+1+1+1+1+1+1+1 = ...etc
a(20) = 1: the only partitions permitted use the digits 0 and 2, so there is just 1, 20 = 2+2+2... ten times.
		

Crossrefs

Programs

  • Haskell
    import Data.List (sort, nub)
    import Data.Char (digitToInt)
    a061827 n =
       p n (map digitToInt $ nub $ sort $ filter (/= '0') $ show n) where
          p _ []        = 0
          p 0 _         = 1
          p m ds'@(d:ds)
            | m < d     = 0
            | otherwise = p (m - d) ds' + p m ds
    -- Reinhard Zumkeller, Aug 01 2011
  • Mathematica
    Length[IntegerPartitions[#,All,DeleteDuplicates@DeleteCases[IntegerDigits[#],0]]]&/@Range[200] (* Sander G. Huisman, Nov 14 2022 *)

Extensions

More terms from David Wasserman, Jul 29 2002

A193513 Number of partitions of n into parts having at least one common digit in decimal representation.

Original entry on oeis.org

1, 1, 2, 2, 3, 2, 4, 2, 4, 3, 4, 3, 8, 5, 9, 9, 13, 9, 16, 12, 18, 16, 23, 20, 31, 30, 38, 38, 51, 49, 64, 62, 79, 77, 95, 101, 118, 118, 143, 145, 179, 181, 216, 223, 267, 286, 325, 341, 399, 416, 485, 500, 575, 600, 686, 735, 823, 864, 981, 1032, 1180
Offset: 0

Views

Author

Reinhard Zumkeller, Jul 30 2011

Keywords

Examples

			a(7) = #{7, 7x1} = 2;
a(8) = #{8, 4+4, 2+2+2+2, 8x1} = 4;
a(9) = #{9, 3+3+3, 9x1} = 3;
a(10) = #{10, 5+5, 2+2+2+2+2, 10x1} = 4;
a(11) = #{11, 10+1, 11x1} = 3;
a(12) = #{12, 11+1, 10+1+1, 6+6, 4+4+4, 3+3+3+3, 6x2, 10x1} = 8;
a(13) = #{13, 12+1, 11+1+1, 10+1+1+1, 13x1} = 5;
a(14) = #{14, 13+1, 12+2, 12+1+1, 11+1+1+1, 10+4x1, 7+7, 7x2, 14x1} = 9.
		

Crossrefs

Programs

  • Haskell
    import Data.List (intersect)
    a193513 n = p "0123456789" n 1 where
       p ""        = 0
       p   0       = 1
       p cds m k
         | m < k     = 0
         | otherwise = p (cds `intersect` show k) (m - k) k + p cds m (k + 1)

Extensions

Thanks to Douglas McNeil, who noticed a program error; data corrected and program fixed by Reinhard Zumkeller, Aug 01 2011
Showing 1-2 of 2 results.