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A235043
Partial sums of the characteristic function of A091209.
6
0, 0, 0, 0, 0, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 2, 2, 2, 2, 2, 2, 3, 3, 3, 3, 3, 3, 4, 4, 4, 4, 4, 4, 4, 4, 4, 4, 4, 4, 4, 4, 5, 5, 5, 5, 5, 5, 5, 5, 5, 5, 6, 6, 6, 6, 6, 6, 6, 6, 6, 6, 6, 6, 6, 6, 6, 6, 6, 6, 7, 7, 7, 7, 7, 7, 7, 7, 8, 8, 8, 8, 9, 9, 9, 9, 9, 9, 10
OFFSET
0,18
COMMENTS
Note that this also works as an inverse function of A091209 in a sense that a(A091209(n)) = n for all n>=1.
LINKS
PROG
(Scheme)
(define (A235043 n) (if (zero? n) n (+ (A235043 (- n 1)) (+ (* (A010051 n) (A091247 n))))))
CROSSREFS
Used to compute A235041. Cf. A010051, A091247, A235044.
Sequence in context: A067099 A098429 A132090 * A071538 A321017 A138194
KEYWORD
nonn
AUTHOR
Antti Karttunen, Jan 02 2014
STATUS
approved