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 1-3 of 3 results.

A351726 Table T(n,k) read by rows: number of compositions of n into k parts of size 1, 5, 10 or 25.

Original entry on oeis.org

1, 0, 1, 0, 0, 1, 0, 0, 0, 1, 0, 0, 0, 0, 1, 0, 1, 0, 0, 0, 1, 0, 0, 2, 0, 0, 0, 1, 0, 0, 0, 3, 0, 0, 0, 1, 0, 0, 0, 0, 4, 0, 0, 0, 1, 0, 0, 0, 0, 0, 5, 0, 0, 0, 1, 0, 1, 1, 0, 0, 0, 6, 0, 0, 0, 1, 0, 0, 2, 3, 0, 0, 0, 7, 0, 0, 0, 1, 0, 0, 0, 3, 6, 0, 0, 0, 8, 0, 0, 0, 1, 0, 0, 0, 0, 4
Offset: 0

Views

Author

R. J. Mathar, Feb 17 2022

Keywords

Examples

			T(7,3)=3 counts 1+1+5 =1+5+1 =5+1+1.
T(10,2)=1 counts 5+5.
T(12,3)=3 counts 1+1+10 =1+10+1 =10+1+1.
T(15,3)=1 counts 5+5+5.
T(16,3)=6 counts 1+5+10 =1+10+5 =5+1+10 =5+10+1 =10+1+5 =10+5+1.
The triangle starts in row n=0 and columns 0<=k<=n:
1
0 1
0 0 1
0 0 0 1
0 0 0 0  1
0 1 0 0  0  1
0 0 2 0  0  0  1
0 0 0 3  0  0  0  1
0 0 0 0  4  0  0  0  1
0 0 0 0  0  5  0  0  0  1
0 1 1 0  0  0  6  0  0  0   1
0 0 2 3  0  0  0  7  0  0   0  1
0 0 0 3  6  0  0  0  8  0   0  0  1
0 0 0 0  4 10  0  0  0  9   0  0  0  1
0 0 0 0  0  5 15  0  0  0  10  0  0  0  1
0 0 2 1  0  0  6 21  0  0   0 11  0  0  0  1
0 0 0 6  4  0  0  7 28  0   0  0 12  0  0  0  1
0 0 0 0 12 10  0  0  8 36   0  0  0 13  0  0  0  1
0 0 0 0  0 20 20  0  0  9  45  0  0  0 14  0  0  0 1
0 0 0 0  0  0 30 35  0  0  10 55  0  0  0 15  0  0 0 1
0 0 1 3  1  0  0 42 56  0   0 11 66  0  0  0 16  0 0 0 1
0 0 0 3 12  5  0  0 56 84   0  0 12 78  0  0  0 17 0 0 0 1
0 0 0 0  6 30 15  0  0 72 120  0  0 13 91  0  0  0 18 0 0 0 1
		

Crossrefs

Cf. A351724 (row sums), A351725 (partitions).

Formula

T(n,0) = 0 if k>0.
G.f.: 1/(1-y*g(x)) where g(x)=x+x^5+x^10+x^25 is the g.f. of column k=1.

A351740 Total number of parts in all partitions of n into parts of size 1, 5, 10 or 25.

Original entry on oeis.org

0, 1, 2, 3, 4, 6, 8, 10, 12, 14, 19, 23, 27, 31, 35, 44, 50, 56, 62, 68, 83, 92, 101, 110, 119, 141, 154, 167, 180, 193, 226, 244, 262, 280, 298, 343, 367, 391, 415, 439, 500, 531, 562, 593, 624, 702, 741, 780, 819, 858, 959, 1008, 1057, 1106, 1155, 1280, 1340
Offset: 0

Views

Author

Alois P. Heinz, Feb 17 2022

Keywords

Crossrefs

Programs

  • Maple
    b:= proc(n, i) option remember; `if`(n=0 or i=1, [1, n], b(n, i-1)+
         (p->`if`(p>n, 0, (t->t+[0, t[1]])(b(n-p, i))))([1, 5, 10, 25][i]))
        end:
    a:= n-> b(n, 4)[2]:
    seq(a(n), n=0..100);

Formula

a(n) = Sum_{k=0..n} k * A351725(n,k).

A351742 Number of partitions of 2n into n parts of size 1, 5, 10 or 25.

Original entry on oeis.org

1, 0, 0, 0, 1, 0, 0, 0, 1, 1, 0, 0, 1, 1, 0, 0, 1, 1, 1, 0, 1, 1, 1, 0, 2, 1, 1, 1, 2, 1, 1, 1, 2, 2, 1, 1, 3, 2, 1, 1, 3, 2, 2, 1, 3, 3, 2, 1, 4, 3, 2, 2, 4, 3, 3, 2, 4, 4, 3, 2, 5, 4, 3, 3, 5, 4, 4, 3, 5, 5, 4, 3, 7, 5, 4, 4, 7, 5, 5, 4, 7, 7, 5, 4, 8, 7, 5
Offset: 0

Views

Author

Alois P. Heinz, Feb 17 2022

Keywords

Examples

			a(0) = 1: [].
a(4) = 1: [{5}^1,{1}^3].
a(24) = 2: [{5}^6,{1}^18], [{25}^1,{1}^23].
a(36) = 3: [{5}^9,{1}^27], [{10}^4,{1}^32], [{25}^1,{5}^3,{1}^32].
		

Crossrefs

Cf. A351725.

Formula

G.f.: -1/(x^37-x^33-x^28+x^24-x^13+x^9+x^4-1).
a(n) = A351725(2n,n).
Showing 1-3 of 3 results.