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A284621 Positions of 0 in A284620. 2
1, 5, 11, 15, 21, 27, 31, 37, 41, 47, 53, 57, 63, 69, 73, 79, 83, 89, 95, 99, 105, 109, 115, 121, 125, 131, 137, 141, 147, 151, 157, 163, 167, 173, 179, 183, 189, 193, 199, 205, 209, 215, 219, 225, 231, 235, 241, 247, 251, 257, 261, 267, 273, 277, 283, 287 (list; graph; refs; listen; history; text; internal format)
OFFSET

1,2

COMMENTS

This sequence and A005843 and A130568 partition the positive integers into sequences with slopes t = 1+sqrt(5), u = 3+sqrt(5), v = 2, where 1/t + 1/u + 1/v = 1.  The positions of 1 in A284620 are given by A005843, and of 2, by A130568.

LINKS

Clark Kimberling, Table of n, a(n) for n = 1..10000

FORMULA

a(n)  = 1 + 2*A001950(n-1) for n >= 1.

EXAMPLE

As a word, A284620 = 012101212101210121..., in which 0 is in positions 1,5,11,15,...

MATHEMATICA

s = Nest[Flatten[# /. {0 -> {0, 1}, 1 -> {0}}] &, {0}, 13]  (* A003849 *)

w = StringJoin[Map[ToString, s]]

w1 = StringReplace[w, {"00" -> "2"}]

st = ToCharacterCode[w1] - 48 (* A284620 *)

Flatten[Position[st, 0]]  (* A284621 *)

Flatten[Position[st, 1]]  (* A005843 *)

Flatten[Position[st, 2]]  (* A130568 *)

CROSSREFS

Cf. A005843, A130568, A284620.

Sequence in context: A314053 A314054 A314055 * A314056 A314057 A314058

Adjacent sequences:  A284618 A284619 A284620 * A284622 A284623 A284624

KEYWORD

nonn,easy

AUTHOR

Clark Kimberling, May 02 2017

STATUS

approved

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Last modified November 16 17:25 EST 2018. Contains 317275 sequences. (Running on oeis4.)