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 A026474 a(n) = least positive integer > a(n-1) and not equal to a(i)+a(j) or a(i)+a(j)+a(k) for 1<=i
 1, 2, 4, 8, 15, 22, 29, 36, 43, 50, 57, 64, 71, 78, 85, 92, 99, 106, 113, 120, 127, 134, 141, 148, 155, 162, 169, 176, 183, 190, 197, 204, 211, 218, 225, 232, 239, 246, 253, 260, 267, 274, 281, 288, 295, 302, 309, 316, 323, 330, 337, 344, 351, 358, 365, 372 (list; graph; refs; listen; history; text; internal format)
 OFFSET 1,2 COMMENTS All h-Stohr sequences have formula: h terms 1,2,..,2^(n-1),..,2^(h-1) and then continue (2^h-1)(n-h)+1. - Henry Bottomley, Feb 04 2000 LINKS Vincenzo Librandi, Table of n, a(n) for n = 1..1000 Eric Weisstein's World of Mathematics, Stoehr Sequence. Index entries for linear recurrences with constant coefficients, signature (2,-1). FORMULA Starts 1, 2, 4 then the numbers 7*(n-3)+1. a(n) = 7*n-20 for n>3. a(n) = 2*a(n-1)-a(n-2) for n>5. G.f.: x*(1+x^2+2*x^3+3*x^4)/(1-x)^2. - Colin Barker, Sep 19 2012 MATHEMATICA Join[{1, 2, 4, 8}, Range[15, 500, 7]] (* Vladimir Joseph Stephan Orlovsky, Jan 27 2012 *) CoefficientList[Series[(1 + x^2 + 2 x^3 + 3 x^4)/(1 - x)^2, {x, 0, 60}], x] (* Vincenzo Librandi, Oct 18 2013 *) LinearRecurrence[{2, -1}, {1, 2, 4, 8, 15}, 60] (* Harvey P. Dale, May 14 2018 *) PROG (MAGMA) [1, 2, 4] cat [7*n+1: n in [1..60]]; // Vincenzo Librandi, Oct 18 2013 (PARI) a(n)=if(n>3, 7*n-20, 2^(n-1)) \\ Charles R Greathouse IV, Sep 17 2015 CROSSREFS Cf. A026472, A026476, A033627, A051039, A051040. Sequence in context: A288313 A213020 A279858 * A301629 A305992 A082562 Adjacent sequences:  A026471 A026472 A026473 * A026475 A026476 A026477 KEYWORD nonn,easy AUTHOR EXTENSIONS More terms from Eric W. Weisstein STATUS approved

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Last modified September 20 05:51 EDT 2019. Contains 327212 sequences. (Running on oeis4.)