A363517 Number of ways to choose 4 disjoint subsets of {1..n} with the same sum and with respectively 1, 2, 3 and 4 distinct elements of {1..n}.

0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 6, 18, 57, 155, 351, 714, 1386, 2495, 4291, 7043, 11234, 17270, 26087, 38105, 54954, 77453, 107816, 146881, 198880, 264222, 348722, 453447, 586339, 747970, 950770, 1193145, 1492469, 1848124, 2280697, 2787353, 3400200, 4110662, 4959054, 5937538

Offset

0,16

Links

Table of n, a(n) for n=0..48.

Example

For n = 15, there are 6 ways to choose the four disjoint subsets:
  15 = 7 + 8 = 4 + 5 + 6 = 1 + 2 + 3 + 9,
  15 = 6 + 9 = 3 + 5 + 7 = 1 + 2 + 4 + 8,
  15 = 6 + 9 = 3 + 4 + 8 = 1 + 2 + 5 + 7,
  15 = 6 + 9 = 2 + 5 + 8 = 1 + 3 + 4 + 7,
  15 = 7 + 8 = 2 + 4 + 9 = 1 + 3 + 5 + 6,
  15 = 7 + 8 = 1 + 5 + 9 = 2 + 3 + 4 + 6, so a(15) = 6.

Crossrefs

Cf. A362717.

Sequence in context: A035070 A075386 A056343 * A227809 A119106 A223468

Adjacent sequences: A363514 A363515 A363516 * A363518 A363519 A363520

Keyword

nonn,nice

Author

Jean-Marc Rebert, Jun 07 2023

Extensions

More terms from David A. Corneth, Jun 08 2023

Status

approved