A323121 Number of compositions of n where the difference between largest and smallest parts equals four.

0, 0, 2, 3, 12, 23, 61, 132, 294, 639, 1377, 2922, 6178, 12953, 27021, 56106, 116030, 239090, 491202, 1006361, 2056755, 4194230, 8536023, 17340787, 35168957, 71217347, 144012394, 290835635, 586637532, 1181960546, 2378920014, 4783326807, 9609050910, 19286596636

Offset

4,3

Links

Alois P. Heinz, Table of n, a(n) for n = 4..3407

Formula

a(n) ~ c * d^n, where d = 1.9659482366454853371899373759344013961513... is the real root of the equation d^5 - d^4 - d^3 - d^2 - d - 1 = 0 or d^6 - 2*d^5 + 1 = 0 and c = 0.53792611681915978492363258130015596032604545873525287924... is the real root of the equation 9584*c^5 - 9584*c^4 + 3160*c^3 - 480*c^2 + 35*c - 1 = 0. - Vaclav Kotesovec, Jan 07 2019

Crossrefs

Column k=4 of A214258.

Sequence in context: A024780 A295366 A323120 * A323122 A323123 A323124

Adjacent sequences: A323118 A323119 A323120 * A323122 A323123 A323124

Keyword

nonn

Author

Alois P. Heinz, Jan 05 2019

Status

approved