A007763 Number of pairs of length n permutations achievable by double-ended priority queue.

1, 4, 32, 392, 6488, 135360, 3408120, 100520432, 3398723928

Offset

1,2

References

M. D. Atkinson and Robert Beals, Priority queues and permutations, SIAM J Comput., 23 (1994), 1225-12430.

Links

Table of n, a(n) for n=1..9.

Sean A. Irvine, Notes on A007763

Crossrefs

Cf. A000272 (single-ended priority queue).

Sequence in context: A201594 A222412 A349601 * A195193 A203435 A349558

Adjacent sequences: A007760 A007761 A007762 * A007764 A007765 A007766

Keyword

nonn,more

Author

mda(AT)cs.st-andrews.ac.uk (Michael Atkinson)

Extensions

Title improved and a(7)-a(9) from Sean A. Irvine, Jan 23 2018

Status

approved