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A214318 Replace the word A214317(n) with its position in A007931. 4
1, 4, 9, 19, 40, 81, 164, 329, 659, 1320, 2641, 5283, 10568, 21137, 42276, 84553, 169107, 338216, 676433, 1352868, 2705737, 5411475, 10822952, 21645905, 43291811, 86583624, 173167249, 346334500, 692669001, 1385338003, 2770676008, 5541352017, 11082704035 (list; graph; refs; listen; history; text; internal format)
OFFSET

1,2

LINKS

Alois P. Heinz, Table of n, a(n) for n = 1..1000

FORMULA

a(n) = A182028(n-1)+2^n-1.

a(n) = 2*a(n-1) + A003842(n-1) for n>1, a(1) = 1. - Alois P. Heinz, Jul 19 2012

EXAMPLE

A214317(5) = 12112 is the 40th term of A007931, so a(5)=40.

MAPLE

S:= proc(n) option remember;

      `if`(n<2, [2-n], [S(n-1)[], S(n-2)[]])

    end:

a:= proc(n) option remember; local k;

      for k while nops(S(k))<n do od;

      `if`(n=1, 1, 2*a(n-1) +S(k)[n])

    end:

seq(a(n), n=1..50);  # Alois P. Heinz, Jul 19 2012

MATHEMATICA

nesting = 6; A003849 = Flatten[Nest[{#, #[[1]]}&, {0, 1}, nesting]]; A182028[n_] := FromDigits[Take[A003849, n+1], 2]; a[n_] := A182028[n-1] + 2^n - 1; Table[a[n], {n, 1, Length[A003849]}] (* Jean-Fran├žois Alcover, Feb 13 2016 *)

CROSSREFS

Cf. A003842, A214317, A007931.

Sequence in context: A052549 A153894 A301137 * A300438 A034479 A326340

Adjacent sequences:  A214315 A214316 A214317 * A214319 A214320 A214321

KEYWORD

nonn

AUTHOR

N. J. A. Sloane, Jul 12 2012

EXTENSIONS

More terms from Alois P. Heinz, Jul 19 2012

STATUS

approved

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Last modified August 13 05:41 EDT 2020. Contains 336442 sequences. (Running on oeis4.)