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 A174354 a(0)=1, a(1)=a(2)=2, a(3)=8 and for n >= 4: if n == 0 (mod 4), a(n)=2, if n == 1 (mod 4), a(n)=8, if n == 2 (mod 4), a(n)=2, if n == 3 (mod 8), a(n)=32, if n = 16k + 15, a(n) = 128*4^k, and if n = 16k+7, a(n) = 128*4^(k-1). 2
 1, 2, 2, 8, 2, 8, 2, 32, 2, 8, 2, 32, 2, 8, 2, 128, 2, 8, 2, 32, 2, 8, 2, 128, 2, 8, 2, 32, 2, 8, 2, 512, 2, 8, 2, 32, 2, 8, 2, 512, 2, 8, 2, 32, 2, 8, 2, 2048, 2, 8, 2, 32, 2, 8, 2, 2048, 2, 8, 2, 32, 2, 8, 2, 8192, 2, 8, 2, 32, 2, 8, 2, 8192, 2, 8, 2, 32, 2, 8, 2, 32768, 2, 8, 2, 32, 2, 8, 2 (list; graph; refs; listen; history; text; internal format)
 OFFSET 0,2 COMMENTS It seems that this sequence gives the numbers of "2" in the successive sets of 2, which appear in A174353. LINKS Antti Karttunen, Table of n, a(n) for n = 0..16384 EXAMPLE a(7) = 32 because 7 = 16*(0) + 7 and a(7) = 128*4^(-1). a(8) = 2 because 8 == 0 (mod 4). MAPLE A174354 := proc(n)     if n  <= 3 then         return op(n+1, [1, 2, 2, 8]) ;     end if;     if n mod 4 =0 then         2  ;     elif n mod 4 =1 then         8  ;     elif n mod 4 = 2 then         2     elif n mod 8 = 3 then         32     elif n mod 16 = 15 then         128*4^((n-15)/16)     elif n mod 16 =7 then         128*4^((n-7)/16-1)     end if; end proc: seq(A174354(n), n=0..240) ; # R. J. Mathar, Feb 29 2016 MATHEMATICA Nest[Append[#1, Which[Mod[#2, 4] == 0, 2, Mod[#2, 4] == 1, 8, Mod[#2, 4] == 2, 2, Mod[#2, 8] == 3, 32, Mod[#2, 16] == 15, 128*4^Quotient[#2, 16], True, 128*4^(Quotient[#2, 16] - 1)]] & @@ {#, Length@ #} &, {1, 2, 2, 8}, 91] (* Michael De Vlieger, Nov 06 2018 *) PROG (PARI) A174354(n) = if(n<=1, 1+n, if(3==n, 8, if(0==((n%4)%2), 2, if(1==(n%4), 8, if(3==(n%8), 32, if(15==(n%16), 128*4^((n-15)/16), 128*4^((n-7)/16-1))))))); \\ (Adapted from Maple-program) - Antti Karttunen, Nov 06 2018 CROSSREFS Cf. A174353. Sequence in context: A208133 A046644 A161915 * A011147 A273168 A098818 Adjacent sequences:  A174351 A174352 A174353 * A174355 A174356 A174357 KEYWORD easy,nonn AUTHOR Richard Choulet, Mar 17 2010 STATUS approved

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Last modified May 19 09:14 EDT 2019. Contains 323390 sequences. (Running on oeis4.)