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A107345 From the binary representation of n: binomial(number of zeros, number of blocks of contiguous zeros). 4
1, 1, 1, 1, 2, 1, 1, 1, 3, 2, 1, 1, 2, 1, 1, 1, 4, 3, 3, 2, 3, 1, 1, 1, 3, 2, 1, 1, 2, 1, 1, 1, 5, 4, 6, 3, 6, 3, 3, 2, 6, 3, 1, 1, 3, 1, 1, 1, 4, 3, 3, 2, 3, 1, 1, 1, 3, 2, 1, 1, 2, 1, 1, 1, 6, 5, 10, 4, 10, 6, 6, 3, 10, 6, 4, 3, 6, 3, 3, 2, 10, 6, 4, 3, 4, 1, 1, 1, 6, 3, 1, 1, 3, 1, 1, 1, 5, 4, 6, 3, 6, 3, 3 (list; graph; refs; listen; history; text; internal format)
OFFSET
0,5
COMMENTS
a(n) = binomial(A023416(n), A087116(n)); a(A003754(n)) = 1.
First occurrence of k: 1, 4, 8, 16, 32, 34, 128, 256, 512, 66, 2048, 4096, 8192, 16384, 130, 65536, 131072, 262144, 524288, 266, 258, ..., . k must occur by 2^k. - Robert G. Wilson v
Record values: 1, 4, 8, 16, 32, 34, 66, 130, 258, 514, 522, 1026, 1034, 2058, 4106, 4138, 8202, 8234, 16394, 16426, 32810, 65578, 65706, 131114, 131242, 262186, 262314, 524458, 1048746, 1049258, 2097322, 2097834, 4194474, 4194986, 8389290, 8391338, ..., . - Robert G. Wilson v
LINKS
MATHEMATICA
f[n_] := Block[{id = IntegerDigits[n, 2]}, Binomial[ Count[id, 0], Floor[(Length@ Split@ id + 1)/2]]]; Table[f@n, {n, 0, 102}] (* Robert G. Wilson v, Apr 01 2008 *)
PROG
(Haskell)
a107345 n = a007318' (a023416 n) (a087116 n)
-- Reinhard Zumkeller, Mar 31 2015
CROSSREFS
Sequence in context: A008479 A331178 A227350 * A358780 A336736 A000688
KEYWORD
nonn
AUTHOR
Reinhard Zumkeller, May 23 2005
STATUS
approved

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Last modified April 19 16:21 EDT 2024. Contains 371794 sequences. (Running on oeis4.)