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A080570
Number of 1's in partition of n-th Ulam number into sum of two distinct Ulam numbers.
1
1, 0, 1, 2, 2, 2, 3, 3, 4, 4, 6, 6, 8, 8, 11, 12, 13, 15, 14, 17, 18, 19, 20, 21, 23, 23, 24, 26, 28, 32, 31, 32, 35, 36, 37, 43, 43, 44, 44, 45, 47, 50, 51, 53, 53, 56, 56, 57, 57, 61, 62, 62, 65, 68, 73, 76, 77, 78, 83, 83, 84, 84, 87, 88, 90, 92, 94, 94, 97, 98, 98, 101, 101
OFFSET
1,4
EXAMPLE
For n=7: A002858(7) = 11 = 3+8 = (1+2)+(2+6) = (1+2)+(2+(2+4)) = (1+2)+(2+(2+(1+3))) = (1+2)+(2+(2+(1+(1+2)))). Number of 1's in (1+2)+(2+(2+(1+(1+2)))) is 3, so a(7) = 3.
CROSSREFS
Cf. A002858.
Sequence in context: A032739 A240868 A029149 * A163001 A239913 A323701
KEYWORD
easy,nonn
AUTHOR
Naohiro Nomoto, Feb 22 2003
STATUS
approved