

A003110


a(n) = number of special odd permutations of 2*n+1.
(Formerly M0393)


4




OFFSET

1,2


COMMENTS

a(n) is the number of odd permutations, pi(0),...,pi(2*n), of 0,...,2*n such that pi(0) = 0 and p(k) = k + pi(k) (mod 2*n+1), k=0,...,2*n is also a permutation of 0,...,2*n.  Sean A. Irvine, Jan 31 2015


REFERENCES

N. J. A. Sloane and Simon Plouffe, The Encyclopedia of Integer Sequences, Academic Press, 1995 (includes this sequence).


LINKS

Table of n, a(n) for n=1..9.
D. H. Lehmer, Some properties of circulants, J. Number Theory 5 (1973), 4354.


CROSSREFS

Cf. A003109 (special even permutations), A003110 (total).
Sequence in context: A210467 A156524 A194027 * A100956 A304915 A216481
Adjacent sequences: A003107 A003108 A003109 * A003111 A003112 A003113


KEYWORD

nonn,more


AUTHOR

N. J. A. Sloane


EXTENSIONS

Name clarified and offset corrected by Sean A. Irvine, Jan 31 2015
a(8)a(9) from Sean A. Irvine, Jan 31 2015


STATUS

approved



