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 A133179 A modular binomial sum transform of 2^n . 3
 1, 1, 1, 3, 1, 3, 5, 15, 1, 3, 5, 15, 17, 51, 85, 255, 1, 3, 5, 15, 17, 51, 85, 255, 257, 771, 1285, 3855, 4369, 13107, 21845, 65535, 1, 3, 5, 15, 17, 51, 85, 255, 257, 771, 1285, 3855, 4369, 13107, 21845, 65535 (list; graph; refs; listen; history; text; internal format)
 OFFSET 0,4 LINKS G. C. Greubel, Table of n, a(n) for the first 50 rows, flattened FORMULA a(n) = Sum_{k=0..floor(n/2)} mod(binomial(n,k),2) * 2^k. EXAMPLE A034868 is: 1; 1; 1, 2; 1, 3; 1, 4, 6; 1, 5, 10 ;... A034868 modulo 2: 1; 1; 1, 0; 1, 1; 1, 0, 0; 1, 1, 0 ;... a(0)=1*2^0 = 1; a(1)=1*2^0 = 1; a(2)=1*2^0+0*2^1 = 1; a(3)=1*2^0+1*2^1 = 3; a(4)=1*2^0+0*2^1+0*2^2 = 1 a(5)=1*2^0+1*2^1+0*2^2 = 3 MATHEMATICA A133179[n_] := Sum[2^k*Mod[Binomial[n, k], 2], {k, 0, Floor[n/2]}]; Table[A133179[n], {n, 0, 50}] (* G. C. Greubel, Aug 11 2017 *) CROSSREFS Cf. A034868, A048896, A101692, A130047. Sequence in context: A050820 A261869 A279697 * A282221 A146908 A279249 Adjacent sequences:  A133176 A133177 A133178 * A133180 A133181 A133182 KEYWORD nonn,tabf AUTHOR Philippe Deléham, Oct 10 2007 STATUS approved

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Last modified June 1 18:43 EDT 2020. Contains 334762 sequences. (Running on oeis4.)