A213452 A001251(n)/2.

0, 0, 1, 6, 35, 221, 1554, 12108, 104293, 986452, 10186669, 114173261, 1381606490, 17963133122, 249838334627, 3702507093782, 58255992451047, 970036965428901, 17043762930794782, 315148172259643152, 6117607922562556061, 124394868793682972996

Offset: 1

Author

N. J. A. Sloane, Jun 12 2012

Keywords

• nonn

References

• F. N. David, M. G. Kendall and D. E. Barton, Symmetric Function and Allied Tables, Cambridge, 1966, p. 262. (Terms for n>=13 are incorrect).
• N. J. A. Sloane, A Handbook of Integer Sequences, Academic Press, 1973 (includes this sequence).

Crossrefs

Cf. A001251.