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A199017
Number of partitions of n into distinct terms of (1,2)-Ulam sequence, cf. A002858.
7
1, 1, 1, 2, 2, 2, 3, 3, 3, 4, 4, 5, 5, 6, 7, 7, 8, 9, 10, 11, 12, 13, 14, 14, 16, 16, 17, 19, 20, 22, 23, 25, 26, 27, 29, 30, 31, 34, 35, 38, 40, 41, 45, 45, 48, 51, 52, 57, 60, 62, 66, 68, 71, 75, 78, 83, 86, 93, 97, 100, 107, 109, 115, 120, 124, 132, 138
OFFSET
0,4
LINKS
EXAMPLE
The first terms of A002858 are 1, 2, 3, 4, 6, 8, 11, 13, 16, 18, ...
a(10) = #{8+2, 6+4, 6+3+1, 4+3+2+1} = 4;
a(11) = #{11, 8+3, 8+2+1, 6+4+1, 6+3+2} = 5;
a(12) = #{11+1, 8+4, 8+3+1, 6+4+2, 6+3+2+1} = 5.
PROG
(Haskell)
a199017 = p a002858_list where
p _ 0 = 1
p (u:us) m | m < u = 0
| otherwise = p us (m - u) + p us m
CROSSREFS
KEYWORD
nonn
AUTHOR
Reinhard Zumkeller, Nov 03 2011
STATUS
approved