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A043687 a(n)=(s(n)-1)/2, where s(n) = n-th number whose base 2 representation has exactly 3 runs. 3
2, 4, 5, 6, 8, 9, 11, 12, 13, 14, 16, 17, 19, 23, 24, 25, 27, 28, 29, 30, 32, 33, 35, 39, 47, 48, 49, 51, 55, 56, 57, 59, 60, 61, 62, 64, 65, 67, 71, 79, 95, 96, 97, 99, 103, 111, 112, 113, 115, 119, 120, 121, 123, 124, 125, 126, 128, 129 (list; graph; refs; listen; history; text; internal format)
OFFSET

1,1

COMMENTS

a(n) = A238246(n) - 1. - Reinhard Zumkeller, Feb 20 2014

LINKS

Vincenzo Librandi, Table of n, a(n) for n = 1..1000

MATHEMATICA

(# - 1)/2&/@Select[Range[1000], Length[Split[IntegerDigits[#, 2]]]==3&] (* Vincenzo Librandi, Feb 22 2014 *)

CROSSREFS

Sequence in context: A328594 A288174 A280998 * A087118 A249115 A039032

Adjacent sequences:  A043684 A043685 A043686 * A043688 A043689 A043690

KEYWORD

nonn,base

AUTHOR

Clark Kimberling

STATUS

approved

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Last modified October 30 10:25 EDT 2020. Contains 338078 sequences. (Running on oeis4.)