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 A166514 Zig-zag function for first two columns of a matrix (take numbers in consecutive pairs). 3
 0, 1, 1, 0, 2, 1, 3, 0, 4, 1, 5, 0, 6, 1, 7, 0, 8, 1, 9, 0, 10, 1, 11, 0, 12, 1, 13, 0, 14, 1, 15, 0, 16, 1, 17, 0, 18, 1, 19, 0, 20, 1, 21, 0, 22, 1, 23, 0, 24, 1, 25, 0, 26, 1, 27, 0, 28, 1, 29, 0, 30, 1, 31, 0, 32, 1, 33, 0, 34, 1, 35, 0, 36, 1, 37, 0, 38, 1, 39, 0, 40, 1, 41, 0, 42, 1, 43, 0 (list; graph; refs; listen; history; text; internal format)
 OFFSET 0,5 LINKS G. C. Greubel, Table of n, a(n) for n = 0..1000 Index entries for linear recurrences with constant coefficients, signature (0,1,0,1,0,-1). FORMULA G.f.: x(1+x-x^2+x^3)/((1+x)^2*(1-x)^2*(1+x^2)) = x(1+x-x^2+x^3)/(1-x^2-x^4+x^6); a(n) = sin(Pi*n/2)/2 + (n-1)(-1)^n/4 + (n+1)/4. MATHEMATICA CoefficientList[Series[(x + x^2 - x^3 + x^4)/((1 + x)^2*(1 - x)^2*(1 + x^2)), {x, 0, 50}], x] (* G. C. Greubel, May 15 2016 *) CROSSREFS Sequence in context: A307742 A297109 A073312 * A246024 A278529 A160588 Adjacent sequences:  A166511 A166512 A166513 * A166515 A166516 A166517 KEYWORD easy,nonn AUTHOR Paul Barry, Oct 16 2009 STATUS approved

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Last modified September 18 18:29 EDT 2019. Contains 327180 sequences. (Running on oeis4.)