|
|
A318586
|
|
Number of integer partitions of n whose sum of reciprocals squared is the reciprocal of an integer.
|
|
6
|
|
|
1, 1, 1, 2, 1, 1, 1, 3, 2, 1, 1, 3, 1, 2, 3, 3, 1, 4, 1, 3, 1, 2, 1, 5, 2, 1, 4, 5, 1, 5, 1, 6, 3, 2, 4, 8, 2, 4, 2, 6, 3, 9, 2, 4, 7, 5, 4, 11, 8, 7, 8, 9, 5, 12, 5, 16, 5, 10, 5, 25, 10, 9, 13, 18, 12, 18, 6, 11, 14, 22, 9, 24, 11, 21, 22, 25, 24, 23, 28, 32
(list;
graph;
refs;
listen;
history;
text;
internal format)
|
|
|
OFFSET
|
1,4
|
|
LINKS
|
|
|
EXAMPLE
|
The a(42) = 9 integer partitions:
(42)
(21,14,7)
(18,9,9,6)
(18,9,9,3,3)
(20,10,4,4,4)
(12,12,12,4,2)
(10,5,5,5,5,5,5,2)
(12,6,6,4,4,4,2,2,2)
(6,6,4,4,4,4,3,3,3,3,2)
|
|
MATHEMATICA
|
Table[Length[Select[IntegerPartitions[n], IntegerQ[1/Total[#^(-2)]]&]], {n, 30}]
|
|
CROSSREFS
|
|
|
KEYWORD
|
nonn
|
|
AUTHOR
|
|
|
EXTENSIONS
|
|
|
STATUS
|
approved
|
|
|
|