A104185 Number of partitions of the set 1, 2, 3, ..., 6n+3 into 2n+1 sets of 3 elements each, such that each 3-element set has the same sum (there are no such partitions unless there are 6n+3 elements).

1, 2, 11, 84, 1296, 24293, 703722, 24212879, 1157746949, 63552536107

Offset

0,2

References

Dossey, Giordano, McCrone and Weir, Mathematics methods and modeling for today's mathematics classroom, p. 134

Links

Table of n, a(n) for n=0..9.

Michael Paul Goldenberg, Online discussion

Example

a(1) = 2 because with 9 elements they can be partitioned (9 5 1) (8 4 3) (7 6 2) or (9 4 2) (8 6 1) (7 5 3)

Prog

Scheme program to generate terms of the sequence available from Joshua Zucker on request.

Crossrefs

Bisection of column k=3 of A203986. - Alois P. Heinz, Jan 09 2012

Sequence in context: A279202 A086406 A158098 * A074604 A135404 A370475

Adjacent sequences: A104182 A104183 A104184 * A104186 A104187 A104188

Keyword

more,nonn

Author

Joshua Zucker, Mar 11 2005

Extensions

More terms from Guenter Stertenbrink

The terms 1157746949, 63552536107 were found by Don Knuth, Sep 04 2009

Status

approved