A238709 Triangular array: t(n,k) = number of partitions p = {x(1) >= x(2) >= ... >= x(k)} such that min(x(j) - x(j-1)) = k.

1, 1, 1, 3, 0, 1, 4, 1, 0, 1, 7, 1, 1, 0, 1, 10, 2, 0, 1, 0, 1, 16, 2, 1, 0, 1, 0, 1, 22, 3, 1, 1, 0, 1, 0, 1, 32, 4, 2, 0, 1, 0, 1, 0, 1, 44, 5, 2, 1, 0, 1, 0, 1, 0, 1, 62, 6, 3, 1, 1, 0, 1, 0, 1, 0, 1, 83, 8, 3, 2, 0, 1, 0, 1, 0, 1, 0, 1, 113, 10, 4, 2, 1

Offset

1,4

Comments

The first two columns are essentially A047967 and A238708. Counting the top row as row 2, the sum of numbers in row n is A000041(n) - 1.

Links

Clark Kimberling, Table of n, a(n) for n = 1..400

Example

row 2:  1
row 3:  1 ... 1
row 4:  3 ... 0 ... 1
row 5:  4 ... 1 ... 0 ... 1
row 6:  7 ... 1 ... 1 ... 0 ... 1
row 7:  10 .. 2 ... 0 ... 1 ... 0 ... 1
row 8:  16 .. 2 ... 1 ... 0 ... 1 ... 0 ... 1
row 9:  22 .. 3 ... 1 ... 1 ... 0 ... 1 ... 0 ... 1
Let m = min(x(j) - x(j-1)); then for row 5, the 4 partitions with m = 0 are 311, 221, 2111, 11111; the 1 partition with m = 1 is 32, and the 1 partition with m = 3 is 41.

Mathematica

z = 25; p[n_, k_] := p[n, k] = IntegerPartitions[n][[k]]; m[n_, k_] := m[n, k] = Min[-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]

Crossrefs

Cf. A238710, A238708.

Sequence in context: A307451 A247629 A178116 * A245120 A226912 A177330

Adjacent sequences: A238706 A238707 A238708 * A238710 A238711 A238712

Keyword

nonn,tabl,easy

Author

Clark Kimberling, Mar 03 2014

Status

approved