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 A003156 A self-generating sequence. (Formerly M3239) 7
 1, 4, 5, 6, 9, 12, 15, 16, 17, 20, 21, 22, 25, 26, 27, 30, 33, 36, 37, 38, 41, 44, 47, 48, 49, 52, 55, 58, 59, 60, 63, 64, 65, 68, 69, 70, 73, 76, 79, 80, 81, 84, 85, 86, 89, 90, 91, 94, 97, 100, 101, 102, 105, 106, 107, 110, 111, 112, 115, 118, 121, 122, 123, 126, 129, 132 (list; graph; refs; listen; history; text; internal format)
 OFFSET 1,2 COMMENTS a(n) is the number of ones before the n-th zero in the Feigenbaum sequence A035263. - Philippe Deléham, Mar 27 2004 Number of odd numbers before the n-th even number in A007413, A007913, A001511, A029883, A033485, A035263, A036585, A065882, A065883, A088172, A092412. - Philippe Deléham, Apr 03 2004 Indices of a in the sequence closed under a -> abc, b -> a, c -> a, starting with a(1) = a; see A092606 where a = 0, b = 2, c = 1. - Philippe Deléham, Apr 12 2004 REFERENCES N. J. A. Sloane and Simon Plouffe, The Encyclopedia of Integer Sequences, Academic Press, 1995 (includes this sequence). LINKS Alois P. Heinz, Table of n, a(n) for n = 1..1000 L. Carlitz, R. Scoville, and V. E. Hoggatt, Jr., Representations for a special sequence, Fibonacci Quarterly 10.5 (1972), 499-518, 550. FORMULA a(n) = A079523(n) - n + 1 = A003157(n) - 2n = A003158(n) - 2n + 1. - Philippe Deléham, Feb 28 2004 a(n) = A036554(n) - n = A072939(n) - n - 1 = 2*A003159(n) - n = A056196(n)/4 - n. - Philippe Deléham, Apr 10 2004 a(n) = sum_{k = 1..n} A080426(k). - Philippe Deléham, Apr 16 2004 MAPLE a:= proc(n) global l; while nops(l) [1, 3\$d, 1][], l) od; `if` (n=1, 1, a(n-1) +l[n]) end: l:= [1]: seq (a(n), n=1..80); # Alois P. Heinz, Oct 31 2009 MATHEMATICA Position[Nest[Flatten[# /. {0 -> {0, 2, 1}, 1 -> {0}, 2 -> {0}}]&, {0}, 7], 0] // Flatten (* Jean-François Alcover, Mar 14 2014 *) PROG (Haskell)  following Deléham a003156 n = a003156_list !! (n-1) a003156_list = scanl1 (+) a080426_list -- Reinhard Zumkeller, Oct 27 2014 CROSSREFS Cf. A001511, A003157, A003158, A003159, A007413, A007913, A029883, A033485, A035263, A036554, A036585, A056196, A065882, A065883, A072939, A079523, A072939, A080426, A088172, A092412, A092606. Sequence in context: A047431 A288695 A182719 * A192360 A115984 A145025 Adjacent sequences:  A003153 A003154 A003155 * A003157 A003158 A003159 KEYWORD nonn AUTHOR EXTENSIONS More terms from Alois P. Heinz, Oct 31 2009 STATUS approved

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Last modified October 23 17:32 EDT 2019. Contains 328373 sequences. (Running on oeis4.)