|
Search: id:A156700
|
|
|
| A156700 |
|
Number of partitions of the set of odd numbers {1, 3, 5, ..., 4*k-1} in two subsets with equal sum, for k = 1, 2, 3, ... |
|
+0
1
|
|
| 0, 1, 1, 4, 10, 34, 103, 346, 1153, 3965, 13746, 48396, 171835, 615966, 2223755, 8082457, 29543309, 108545916, 400623807, 1484716135, 5522723344, 20612084010, 77164686511, 289688970195, 1090342139349, 4113620233260, 15553877949800
(list; graph; listen)
|
|
|
OFFSET
|
1,4
|
|
|
EXAMPLE
|
For k=2: {1, 7}U{3, 5}. For k=3: {1, 3, 5, 9}U{7, 11}. For k=4: {1, 3, 13, 15}U{5, 7, 9, 11}, {1, 5, 11, 15}U{3, 7, 9, 13}, {1, 7, 9, 15}U{3, 5, 11, 13}, {3, 5, 9, 15}U{1, 7, 11, 13}
|
|
MAPLE
|
with (numtheory): b:= proc() option remember; local i, j, t; `if` (args[1]=0, `if` (nargs=2, 1, b(args[t] $t=2..nargs)), add (`if` (args[j] -args[nargs] <0, 0, b(sort ([seq (args[i] -`if` (i=j, args[nargs], 0), i=1..nargs-1)])[], args[nargs]-2)), j=1..nargs-1)) end: a:= n-> b((2*n^2)$2, 4*n-1)/2: seq (a(n), n=1..40); [From Alois P. Heinz (heinz(AT)hs-heilbronn.de), Sep 06 2009]
|
|
CROSSREFS
|
Sequence in context: A140725 A005630 A100507 this_sequence A149173 A149174 A030003
Adjacent sequences: A156697 A156698 A156699 this_sequence A156701 A156702 A156703
|
|
KEYWORD
|
nonn
|
|
AUTHOR
|
Wim Couwenberg (wim.couwenberg(AT)gmail.com), Feb 13 2009
|
|
EXTENSIONS
|
Extended beyond a(18) by Alois P. Heinz (heinz(AT)hs-heilbronn.de), Sep 06 2009
|
|
|
Search completed in 0.002 seconds
|
