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Search: id:A116522
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| A116522 |
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a(0)=1, a(1)=1, a(n)=7a(n/2) for n=2,4,6,..., a(n)=6a((n-1)/2)+a((n+1)/2) for n=3,5,7,.... |
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+0
1
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| 0, 1, 7, 13, 49, 55, 91, 127, 343, 349, 385, 421, 637, 673, 889, 1105, 2401, 2407, 2443, 2479, 2695, 2731, 2947, 3163, 4459, 4495, 4711, 4927, 6223, 6439, 7735, 9031, 16807, 16813, 16849, 16885, 17101, 17137, 17353, 17569, 18865, 18901, 19117, 19333
(list; graph; listen)
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OFFSET
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0,3
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COMMENT
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A 7-divide version of A084230.
The Harborth : f(2^k)=3^k suggests that a family of sequences of the form: f(2^k)=Prime[n]^k
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REFERENCES
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Harborth, H. Number of Odd Binomial Coefficients. Proc. Amer. Math. Soc. 62, 19-22, 1977
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LINKS
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Eric Weisstein's World of Mathematics, Stolarsky-Harborth Constant
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MAPLE
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a:=proc(n) if n=0 then 0 elif n=1 then 1 elif n mod 2 = 0 then 7*a(n/2) else 6*a((n-1)/2)+a((n+1)/2) fi end: seq(a(n), n=0..47);
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MATHEMATICA
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b[0] := 0 b[1] := 1 b[n_?EvenQ] := b[n] = 7*b[n/2] b[n_?OddQ] := b[n] = 6*b[(n - 1)/2] + b[(n + 1)/2] a = Table[b[n], {n, 1, 25}]
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CROSSREFS
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Cf. A006046, A077465.
Sequence in context: A087820 A023286 A134039 this_sequence A108056 A018562 A112540
Adjacent sequences: A116519 A116520 A116521 this_sequence A116523 A116524 A116525
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KEYWORD
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nonn
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AUTHOR
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Roger Bagula (rlbagulatftn(AT)yahoo.com), Mar 15 2006
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EXTENSIONS
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Edited by njas, Apr 16 2005
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