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A306738
Number of permutations of [n] allowing i->i+j (mod n), j=0..ceiling(n/2)-1.
1
1, 1, 1, 2, 2, 13, 20, 144, 264, 2783, 6208, 79118, 204448, 3182225, 9411840, 170576156, 566725760, 11804363619, 43573050368, 1023207993178, 4152609019392, 108681408827381, 481065936784384, 13880706183899752
OFFSET
0,4
FORMULA
a(n) = A008305(n,ceiling(n/2)).
CROSSREFS
Cf. A008305.
Sequence in context: A340587 A347080 A141575 * A151352 A155915 A173466
KEYWORD
nonn
AUTHOR
Alois P. Heinz, Mar 06 2019
STATUS
approved