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 A163617 a(2*n) = 2*a(n), a(2*n + 1) = 2*a(n) + 2 + (-1)^n, for all n in Z. 15
 0, 3, 6, 7, 12, 15, 14, 15, 24, 27, 30, 31, 28, 31, 30, 31, 48, 51, 54, 55, 60, 63, 62, 63, 56, 59, 62, 63, 60, 63, 62, 63, 96, 99, 102, 103, 108, 111, 110, 111, 120, 123, 126, 127, 124, 127, 126, 127, 112, 115, 118, 119, 124, 127, 126, 127, 120, 123, 126, 127, 124, 127, 126 (list; graph; refs; listen; history; text; internal format)
 OFFSET 0,2 COMMENTS Fibbinary numbers (A003714) give all integers n>=0 for which a(n) = 3*n. From Antti Karttunen, Feb 21 2016: (Start) Fibbinary numbers give also all integers n >= 0 for which a(n) = A048724(n). Note that there are also other multiples of three in the sequence, like for example A163617(99) = 231 ("11100111" in binary) = 3*77, while 77 ("1001101" in binary) is not included in A003714. Note that 99 is "1100011" in binary. (End) LINKS Reinhard Zumkeller, Table of n, a(n) for n = 0..10000 FORMULA a(n) = -A163618(-n) for all n in ZZ. Conjecture: a(n) = A003188(n) + (6*n+1-(-1)^n)/4. - Velin Yanev, Dec 17 2016 EXAMPLE G.f. = 3*x + 6*x^2 + 7*x^3 + 12*x^4 + 15*x^5 + 14*x^6 + 15*x^7 + 24*x^8 + 27*x^9 + ... MAPLE A163617 := n -> Bits:-Or(2*n, n): seq(A163617(n), n=0..62); # Peter Luschny, Sep 23 2019 MATHEMATICA Table[BitOr[n, 2*n], {n, 0, 100}] (* Vladimir Joseph Stephan Orlovsky, Jul 19 2011 *) PROG (PARI) {a(n) = bitor(n, n<<1)}; (PARI) {a(n) = if( n==0 || n==-1, n, 2 * a(n \ 2) + (n%2) * (2 + (-1)^(n \ 2)))}; (Haskell) import Data.Bits ((.|.), shiftL) a163617 n = n .|. shiftL n 1 :: Integer -- Reinhard Zumkeller, Mar 06 2013 (Scheme) (define (A163617 n) (A003986bi n (+ n n))) ;; Here A003986bi implements dyadic bitwise-OR operation (see A003986) - Antti Karttunen, Feb 21 2016 CROSSREFS Cf. A003986, A048724, A213370, A163618. Cf. also A269161. Sequence in context: A226228 A269174 A161903 * A189634 A047705 A309839 Adjacent sequences:  A163614 A163615 A163616 * A163618 A163619 A163620 KEYWORD nonn AUTHOR Michael Somos, Aug 01 2009 EXTENSIONS Comment about Fibbinary numbers rephrased by Antti Karttunen, Feb 21 2016 STATUS approved

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Last modified December 15 03:48 EST 2019. Contains 329990 sequences. (Running on oeis4.)