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.

A238710 Triangular array: t(n,k) = number of partitions p = {x(1) >= x(2) >= ... >= x(k)} such that max(x(j) - x(j-1)) = k.

Original entry on oeis.org

1, 1, 1, 2, 1, 1, 1, 3, 1, 1, 3, 3, 2, 1, 1, 1, 6, 3, 2, 1, 1, 3, 6, 6, 2, 2, 1, 1, 2, 10, 6, 5, 2, 2, 1, 1, 3, 11, 11, 6, 4, 2, 2, 1, 1, 1, 16, 13, 10, 5, 4, 2, 2, 1, 1, 5, 17, 19, 12, 9, 4, 4, 2, 2, 1, 1, 1, 24, 24, 18, 11, 8, 4, 4, 2, 2, 1, 1, 3, 27, 34
Offset: 1

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Author

Clark Kimberling, Mar 03 2014

Keywords

Comments

The first two columns are essentially A032741 and A237665. Counting the top row as row 2, the sum of numbers in row n is A000041(n) - 1.

Examples

			row 2:  1
row 3:  1 ... 1
row 4:  2 ... 1 ... 1
row 5:  1 ... 3 ... 1 ... 1
row 6:  3 ... 3 ... 2 ... 1 ... 1
row 7:  1 ... 6 ... 3 ... 2 ... 1 ... 1
row 8:  3 ... 6 ... 6 ... 2 ... 2 ... 1 ... 1
row 9:  2 ... 10 .. 6 ... 5 ... 2 ... 2 ... 1 ... 1
Let m = max(x(j) - x(j-1)); then for row 5, the 1 partition with m = 0 is 11111; the 3 partitions with m = 1 are 32, 221, 2111; the 1 partition with m = 2 is 311, and the 1 partition with m = 3 is 41.
		

Crossrefs

Programs

  • Mathematica
    z = 25; p[n_, k_] := p[n, k] = IntegerPartitions[n][[k]]; m[n_, k_] := m[n, k] = Max[-Differences[p[n, k]]]; c[n_] := Table[m[n, h], {h, 1, PartitionsP[n]}]; v = Table[Count[c[n], h], {n, 2, z}, {h, 0, n - 2}]; Flatten[v]
    TableForm[v]