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.

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A173302 Irregular triangle by rows, generated from an array with A000041 starting again at columns (2^n - 1), n=1,2,3,...

Original entry on oeis.org

1, 1, 1, 2, 1, 3, 2, 1, 5, 3, 1, 7, 5, 2, 11, 7, 3, 15, 11, 5, 1, 22, 15, 7, 1, 30, 22, 11, 2, 42, 30, 15, 3, 56, 42, 22, 5, 77, 56, 30, 7, 101, 77, 42, 11, 135, 101, 56, 15, 176, 135, 77, 22, 1, 231, 176, 101, 30, 1, 297, 231, 135, 42, 2
Offset: 0

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Author

Gary W. Adamson, Feb 15 2010

Keywords

Comments

Sum of finite difference terms of the array create triangle A173304.
Row sums = A173303.

Examples

			The generating array =
1, 1, 2, 3, 5, 7, 11, 15, 22, 30, 42, 56, 77, 101, 135, 176,...
...1, 1, 2, 3, 5,..7,.11, 15, 22, 30, 42, 56, .77, 101, 135,...
.........1, 1, 2,..3...5,..7, 11, 15, 22, 30, .42, .56, .77,...
.......................1,..1,..2,..3,..5,..7,..11,..15,..22,...
..........................................................1,...
...then columns become the rows of triangle A173302:
1;
1, 1;
2, 1;
3, 2, 1;
5, 3, 1;
7, 5, 2;
11, 7, 3;
15, 11, 5, 1;
22, 15, 7, 1;
30, 22, 11, 2;
42, 30, 15, 3;
56, 42, 22, 5;
77, 56, 30, 7;
101, 77, 4, 11;
135, 101, 56, 15;
176, 135, 77, 22, 1;
...
		

Crossrefs

Formula

Create an array with A000041 in row 0, then A000041 starts anew under successive columns (1, 3, 7, 15, 31,...). (Cf. A173301).
Columns of the array = rows of A173302.

A173303 Row sums of triangle A173302.

Original entry on oeis.org

1, 2, 3, 6, 9, 14, 21, 32, 45, 65, 90, 125, 170, 231, 307, 411, 539, 707, 917, 1188, 1522, 1950, 2475, 3137, 3949, 4962, 6195, 7725, 9579, 11856, 14610, 17971, 22012, 26919, 32798, 39892, 48367, 58541, 70647, 85123, 102291, 122724, 146891, 175545, 209322
Offset: 0

Views

Author

Gary W. Adamson, Feb 15 2010

Keywords

Comments

Each term is a sum of partition numbers.

Examples

			a(7) = 32 = (1 + 5 + 11 + 15), = p(0) + p(4) + p(6) + p(7).
		

Crossrefs

Row sums of A173302.

Programs

  • PARI
    a(n) = sum(k=0, logint(n+1, 2), numbpart(n + 1 - 2^k)) \\ Andrew Howroyd, Aug 10 2018

Formula

a(n) = Sum_{k >=0, 2^k <= n + 1} A000041(n + 1 - 2^k). - Andrew Howroyd, Aug 10 2018

Extensions

Terms a(21) and beyond from Andrew Howroyd, Aug 10 2018
Showing 1-2 of 2 results.