A152140 Triangle read by rows: T(n,k) (n>=0, 0<=k<=n) = number of partitions of n into k odd parts.

1, 0, 1, 0, 0, 1, 0, 1, 0, 1, 0, 0, 1, 0, 1, 0, 1, 0, 1, 0, 1, 0, 0, 2, 0, 1, 0, 1, 0, 1, 0, 2, 0, 1, 0, 1, 0, 0, 2, 0, 2, 0, 1, 0, 1, 0, 1, 0, 3, 0, 2, 0, 1, 0, 1, 0, 0, 3, 0, 3, 0, 2, 0, 1, 0, 1, 0, 1, 0, 4, 0, 3, 0, 2, 0, 1, 0, 1, 0, 0, 3, 0, 5, 0, 3, 0, 2, 0, 1, 0, 1, 0, 1, 0, 5, 0, 5, 0, 3, 0, 2, 0, 1, 0, 1

Offset: 0

Author

R. J. Mathar, Sep 25 2009, offset corrected Jul 09 2012

Keywords

• nonn
• tabl

Comments

The number of partitions of n into k odd parts is equal to the number of partitions of (n+k)/2 into k parts; or equivalently the number of partitions of (n-k)/2 into at most k parts. - Franklin T. Adams-Watters, Sep 25 2009

Examples

			n= 0, k= 0: [];
n= 1, k= 1: [1] ;
n= 2, k= 2: [1, 1] ;
n= 3, k= 1: [3] ;
n= 3, k= 3: [1, 1, 1] ;
n= 4, k= 2: [1, 3] ;
n= 4, k= 4: [1, 1, 1, 1];
n= 5, k= 1: [5];
n= 5, k= 3: [1, 1, 3];
n= 5, k= 5: [1, 1, 1, 1, 1];
n= 6, k= 2: [3, 3] or [1, 5];
n= 6, k= 4: [1, 1, 1, 3];
n= 6, k= 6: [1, 1, 1, 1, 1, 1];
Triangle begins:
1
0 1
0 0 1
0 1 0 1
0 0 1 0 1
0 1 0 1 0 1
0 0 2 0 1 0 1
0 1 0 2 0 1 0 1
0 0 2 0 2 0 1 0 1
0 1 0 3 0 2 0 1 0 1
0 0 3 0 3 0 2 0 1 0 1
0 1 0 4 0 3 0 2 0 1 0 1
0 0 3 0 5 0 3 0 2 0 1 0 1
0 1 0 5 0 5 0 3 0 2 0 1 0 1
0 0 4 0 6 0 5 0 3 0 2 0 1 0 1
0 1 0 7 0 7 0 5 0 3 0 2 0 1 0 1
0 0 4 0 9 0 7 0 5 0 3 0 2 0 1 0 1
0 1 0 8 0 10 0 7 0 5 0 3 0 2 0 1 0 1
0 0 5 0 11 0 11 0 7 0 5 0 3 0 2 0 1 0 1
0 1 0 10 0 13 0 11 0 7 0 5 0 3 0 2 0 1 0 1
0 0 5 0 15 0 14 0 11 0 7 0 5 0 3 0 2 0 1 0 1
0 1 0 12 0 18 0 15 0 11 0 7 0 5 0 3 0 2 0 1 0 1
0 0 6 0 18 0 20 0 15 0 11 0 7 0 5 0 3 0 2 0 1 0 1
0 1 0 14 0 23 0 21 0 15 0 11 0 7 0 5 0 3 0 2 0 1 0 1
0 0 6 0 23 0 26 0 22 0 15 0 11 0 7 0 5 0 3 0 2 0 1 0 1
0 1 0 16 0 30 0 28 0 22 0 15 0 11 0 7 0 5 0 3 0 2 0 1 0 1
0 0 7 0 27 0 35 0 29 0 22 0 15 0 11 0 7 0 5 0 3 0 2 0 1 0 1
0 1 0 19 0 37 0 38 0 30 0 22 0 15 0 11 0 7 0 5 0 3 0 2 0 1 0 1
0 0 7 0 34 0 44 0 40 0 30 0 22 0 15 0 11 0 7 0 5 0 3 0 2 0 1 0 1
0 1 0 21 0 47 0 49 0 41 0 30 0 22 0 15 0 11 0 7 0 5 0 3 0 2 0 1 0 1
0 0 8 0 39 0 58 0 52 0 42 0 30 0 22 0 15 0 11 0 7 0 5 0 3 0 2 0 1 0 1
0 1 0 24 0 57 0 65 0 54 0 42 0 30 0 22 0 15 0 11 0 7 0 5 0 3 0 2 0 1 0 1
0 0 8 0 47 0 71 0 70 0 55 0 42 0 30 0 22 0 15 0 11 0 7 0 5 0 3 0 2 0 1 0 1
0 1 0 27 0 70 0 82 0 73 0 56 0 42 0 30 0 22 0 15 0 11 0 7 0 5 0 3 0 2 0 1 0 1
0 0 9 0 54 0 90 0 89 0 75 0 56 0 42 0 30 0 22 0 15 0 11 0 7 0 5 0 3 0 2 0 1 0 1
0 1 0 30 0 84 0 105 0 94 0 76 0 56 0 42 0 30 0 22 0 15 0 11 0 7 0 5 0 3 0 2 0 1 0 1
		

Links

• Alois P. Heinz, Rows n = 0..140, flattened

Crossrefs

Cf. A000009 (row sums), A097304, A107379, A152146, A152157.

Programs

Maple

b:= proc(n, i) option remember; local j; if n=0 then 1
      elif i<1 then 0 elif irem(i, 2)=0 then b(n, i-1)
      else []; for j from 0 to n/i do zip((x, y)->x+y, %,
      [0$j, b(n-i*j, i-2)], 0) od; %[] fi
    end:
T:= n-> b(n$2):
seq(T(n), n=0..13);  # Alois P. Heinz, May 31 2013

Mathematica

nn = 10; CoefficientList[
Series[Product[1/(1 - y x^i), {i, 1, nn, 2}], {x, 0, nn}], {x, y}] (* Geoffrey Critzer, May 31 2013 *)