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.

A114374 Number of partitions of n into parts that are not squarefree.

Original entry on oeis.org

1, 0, 0, 0, 1, 0, 0, 0, 2, 1, 0, 0, 3, 1, 0, 0, 5, 2, 2, 0, 7, 3, 2, 0, 11, 6, 4, 3, 15, 8, 6, 3, 22, 13, 11, 6, 34, 18, 15, 9, 46, 27, 24, 17, 64, 43, 33, 23, 89, 60, 51, 37, 124, 84, 78, 51, 166, 119, 109, 78, 226, 168, 152, 118, 300, 228, 215, 166, 404, 313, 300, 230, 546, 421, 409
Offset: 0

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Author

Reinhard Zumkeller, Feb 09 2006

Keywords

Comments

a(A078135(n)) = 0; a(A078137(n)) > 0.

Examples

			a(12) = #{2*2*3, 2*2*2 + 2*2, 2*2 + 2*2 + 2*2} = 3;
a(13) = #{3*3 + 2*2} = 1.
		

Crossrefs

Programs

  • Haskell
    a114374 = p a013929_list where
       p _          0 = 1
       p ks'@(k:ks) m = if m < k then 0 else p ks' (m - k) + p ks m
    -- Reinhard Zumkeller, Jun 01 2015
  • Maple
    with(numtheory):
    b:= proc(n, i) option remember;
          `if`(n=0, 1, `if`(i<1, 0, b(n, i-1)+
          `if`(i>n or issqrfree(i), 0, b(n-i, i))))
        end:
    a:= n-> b(n$2):
    seq(a(n), n=0..100);  # Alois P. Heinz, Jun 03 2015
  • Mathematica
    b[n_, i_] := b[n, i] = If[n==0, 1, If[i<1, 0, b[n, i-1] + If[i>n || SquareFreeQ[i], 0, b[n-i, i]]]]; a[n_] := b[n, n]; Table[a[n], {n, 0, 100}] (* Jean-François Alcover, Jun 30 2015, after Alois P. Heinz *)

Formula

a(n) = A000041(n) - A073576(n) - A117395(n). - Reinhard Zumkeller, Mar 11 2006
G.f.: Product_{k>=1} (1 - mu(k)^2*x^k)/(1 - x^k), where mu(k) is the Moebius function (A008683). - Ilya Gutkovskiy, Dec 30 2016

Extensions

Offset changed and a(0)=1 prepended by Reinhard Zumkeller, Jun 01 2015