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
Examples
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)
References
- Dossey, Giordano, McCrone and Weir, Mathematics methods and modeling for today's mathematics classroom, p. 134
Links
- Michael Paul Goldenberg, Online discussion
Crossrefs
Bisection of column k=3 of A203986. - Alois P. Heinz, Jan 09 2012
Programs
-
Scheme
; Program to generate terms of the sequence available from Joshua Zucker on request.
Extensions
More terms from Guenter Stertenbrink
The terms 1157746949, 63552536107 were found by Don Knuth, Sep 04 2009