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.

A101417 Number of partitions of n into parts without powers of 2.

Original entry on oeis.org

1, 0, 0, 1, 0, 1, 2, 1, 1, 3, 3, 3, 6, 5, 6, 10, 9, 12, 17, 17, 22, 28, 30, 37, 48, 52, 62, 78, 86, 103, 127, 141, 166, 201, 227, 266, 317, 358, 417, 492, 560, 647, 757, 860, 991, 1153, 1309, 1503, 1738, 1971, 2257, 2594, 2941, 3356, 3843, 4351, 4948, 5644, 6382, 7240
Offset: 0

Views

Author

Reinhard Zumkeller, Jan 16 2005

Keywords

Examples

			a(12) = #{3+3+3+3, 6+3+3, 6+6, 7+5, 9+3, 12} = 6.
From _Gus Wiseman_, Jan 07 2019: (Start)
The a(3) = 1 through a(14) = 5 integer partitions (A = 10, ..., E = 14):
  (3)  (5)  (6)   (7)  (53)  (9)    (A)   (B)    (C)     (D)    (E)
            (33)             (63)   (55)  (65)   (66)    (76)   (77)
                             (333)  (73)  (533)  (75)    (A3)   (95)
                                                 (93)    (553)  (B3)
                                                 (633)   (733)  (653)
                                                 (3333)         (5333)
(End)
		

Crossrefs

Programs

  • Maple
    g:= product(1-x^(2^j),j=0..15)/product(1-x^i,i=1..75): gser:= series(g, x=0,62): seq(coeff(gser,x,n),n=0..59); # Emeric Deutsch, Mar 29 2006
  • Mathematica
    Table[Length[Select[IntegerPartitions[n],And@@Not/@IntegerQ/@Log[2,#]&]],{n,20}] (* Gus Wiseman, Jan 07 2019 *)

Formula

G.f.: Product_{j>=1} (1-x^(2^j)) / Product_{i>=2} (1-x^i). - Emeric Deutsch, Mar 29 2006