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A206557
Number of 7's in the last section of the set of partitions of n.
2
0, 0, 0, 0, 0, 0, 1, 0, 1, 1, 2, 2, 4, 5, 7, 9, 13, 16, 23, 28, 39, 48, 64, 79, 104, 128, 165, 204, 258, 317, 399, 487, 606, 739, 912, 1105, 1356, 1637, 1994, 2400, 2906, 3485, 4199, 5016, 6015, 7164, 8553, 10151, 12076, 14286, 16930, 19974, 23588, 27749
OFFSET
1,11
COMMENTS
Zero together with the first differences of A024791. Also number of occurrences of 7 in all partitions of n that do not contain 1 as a part. For the definition of "last section of n" see A135010. It appears that the sums of seven successive terms give the partition numbers A000041.
FORMULA
It appears that A000041(n) = Sum_{j=1..7} a(n+j), n >= 0.
PROG
(Sage) A206557 = lambda n: sum(list(p).count(7) for p in Partitions(n) if 1 not in p)
CROSSREFS
KEYWORD
nonn
AUTHOR
Omar E. Pol, Feb 09 2012
STATUS
approved