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%I #26 Mar 31 2017 00:34:30
%S 1,4,9,19,40,81,164,329,659,1320,2641,5283,10568,21137,42276,84553,
%T 169107,338216,676433,1352868,2705737,5411475,10822952,21645905,
%U 43291811,86583624,173167249,346334500,692669001,1385338003,2770676008,5541352017,11082704035
%N Replace the word A214317(n) with its position in A007931.
%H Alois P. Heinz, <a href="/A214318/b214318.txt">Table of n, a(n) for n = 1..1000</a>
%F a(n) = A182028(n-1)+2^n-1.
%F a(n) = 2*a(n-1) + A003842(n-1) for n>1, a(1) = 1. - _Alois P. Heinz_, Jul 19 2012
%e A214317(5) = 12112 is the 40th term of A007931, so a(5)=40.
%p S:= proc(n) option remember;
%p `if`(n<2, [2-n], [S(n-1)[], S(n-2)[]])
%p end:
%p a:= proc(n) option remember; local k;
%p for k while nops(S(k))<n do od;
%p `if`(n=1, 1, 2*a(n-1) +S(k)[n])
%p end:
%p seq(a(n), n=1..50); # _Alois P. Heinz_, Jul 19 2012
%t 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-François Alcover_, Feb 13 2016 *)
%Y Cf. A003842, A214317, A007931.
%K nonn
%O 1,2
%A _N. J. A. Sloane_, Jul 12 2012
%E More terms from _Alois P. Heinz_, Jul 19 2012
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