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A199123 Number of partitions of n into distinct terms of (2,3)-Ulam sequence, cf. A001857. 6
1, 0, 1, 1, 0, 2, 0, 2, 2, 2, 3, 2, 3, 3, 4, 4, 5, 5, 6, 6, 6, 8, 8, 9, 11, 10, 12, 14, 12, 17, 16, 17, 22, 19, 24, 25, 25, 30, 30, 33, 37, 37, 42, 45, 46, 52, 54, 57, 64, 66, 69, 79, 76, 87, 93, 91, 109, 105, 115, 126, 123, 140, 144, 151, 166, 169, 180, 193 (list; graph; refs; listen; history; text; internal format)
OFFSET
0,6
LINKS
Eric Weisstein's World of Mathematics, Ulam Sequence
Wikipedia, Ulam number
EXAMPLE
The first terms of A001857 are 2, 3, 5, 7, 8, 9, 13, 14, 18, 19, 24, ...
a(20) = #{18+2, 13+7, 13+5+2, 9+8+3, 8+7+5, 8+7+3+2} = 6;
a(21) = #{19+2, 18+3, 14+7, 14+5+2, 13+8, 13+5+3, 9+7+5, 9+7+3+2} = 8.
PROG
(Haskell)
a199123 = p a001857_list where
p _ 0 = 1
p (u:us) m | m < u = 0
| otherwise = p us (m - u) + p us m
CROSSREFS
Sequence in context: A036461 A244478 A261153 * A325589 A291308 A207944
KEYWORD
nonn
AUTHOR
Reinhard Zumkeller, Nov 03 2011
STATUS
approved

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Last modified June 24 16:36 EDT 2024. Contains 373680 sequences. (Running on oeis4.)