A007905 Conflicts during insertions into exchange trees on n nodes.

0, 0, 1, 4, 30, 216, 1440, 11040, 112560, 1229760, 14333760, 179988480, 2259290880, 30656102400, 446269824000, 6949355212800, 123855443712000, 2320686111744000, 45616912653312000, 939726185029632000, 20166054423330816000

Offset

0,4

Links

Table of n, a(n) for n=0..20.

Markus E. Nebel, Digital Search Trees with Keys of Variable Length, R.A.I.R.O. Theoretical Informatics and Applications 30 (6), 1996, 507 - 520 (see (3) on p. 6).

Index entries for sequences related to trees

Formula

See PARI program.

Prog

(PARI) b(n) = if (n == 0, 0, if (n == 1, 0, b(n\2) + b((n-1)\2) + (n-1)/n));
lista(nn) = {for(n=0, nn, print1(n!*b(n), ", "); ); } \\ Michel Marcus, Aug 13 2013

Crossrefs

Sequence in context: A246151 A094567 A134093 * A084976 A000313 A082144

Adjacent sequences: A007902 A007903 A007904 * A007906 A007907 A007908

Keyword

nonn

Author

Markus Nebel [ nebel(AT)sads.informatik.uni-frankfurt.de ]

Extensions

More terms from Michel Marcus, Aug 15 2013

Status

approved