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A116555 Anti-Harborth alternating chaotic sequence, 6th type. 6
1, 9, 10, 81, 91, 90, 109, 729, 820, 819, 991, 810, 991, 981, 1180, 6561, 7399, 7380, 8929, 7371, 9010, 8919, 10729, 7290, 9091, 8919, 10720, 8829, 10801, 10620, 12781, 59049, 66790, 66591, 80551, 66420, 81199, 80361, 96670, 66339, 82639, 81090 (list; graph; refs; listen; history; text; internal format)
OFFSET

0,2

COMMENTS

There seem to be a range of sequences of {odd, even} the type: b(2*n+1) = (2*m-1)*b(n), b(2*n+2) = 2*m*b(n) + b(n - 1).

LINKS

G. C. Greubel, Table of n, a(n) for n = 0..2500

H. Harborth, Number of Odd Binomial Coefficients, Proc. Amer. Math. Soc. 62, 19-22, 1977.

Eric Weisstein's World of Mathematics, Stolarsky-Harborth Constant

FORMULA

From G. C. Greubel, Oct 30 2016: (Start)

a(2*n+1) = 9*a(n).

a(2*n+2) = 10*a(n) + a(n-1). (End)

MATHEMATICA

b[0] := 0; b[1] := 1; b[n_?EvenQ] := b[n] = 9*b[n/2]; b[n_?OddQ] := b[n] = 10*b[(n - 1)/2] + b[(n - 3)/2]; a = Table[b[n], {n, 1, 70}]

CROSSREFS

Cf. A116528, A116529, A116552, A116553, A116554.

Sequence in context: A101242 A033046 A025635 * A038300 A201948 A249311

Adjacent sequences:  A116552 A116553 A116554 * A116556 A116557 A116558

KEYWORD

nonn,obsc

AUTHOR

Roger L. Bagula, Mar 15 2006

EXTENSIONS

Name change by G. C. Greubel, Oct 30 2016

STATUS

approved

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Last modified December 18 23:46 EST 2018. Contains 318245 sequences. (Running on oeis4.)