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 A062547 a(n) is least odd integer not a partial sum of 1, 3, ..., a(n-1). 3
 1, 3, 5, 7, 17, 19, 53, 55, 161, 163, 485, 487, 1457, 1459, 4373, 4375, 13121, 13123, 39365, 39367, 118097, 118099, 354293, 354295, 1062881, 1062883, 3188645, 3188647, 9565937, 9565939, 28697813, 28697815, 86093441, 86093443, 258280325 (list; graph; refs; listen; history; text; internal format)
 OFFSET 0,2 COMMENTS Odd-indexed terms = A048473; even-indexed terms a(2n) = a(2n-1)+2; a(2*n) = A048473(n) and also, for n > 0, a(2*n) = 3*a(2*n-1) - 4; a(2*n+1) = a(2*n) + 2 = A052919(n+1). LINKS Index entries for linear recurrences with constant coefficients, signature (-1,3,3). FORMULA From Bruno Berselli, Jan 28 2011: (Start) G.f.: (1+4*x+5*x^2)/((1+x)*(1-3*x^2)); a(n) = -a(n-1) + 3*a(n-2) + 3*a(n-3) for n > 2. a(n) = 2*3^((2*n + (-1)^n - 1)/4) - (-1)^n. (End) EXAMPLE Partial sums of 1;3;5 are 1;3;4;5;6;8;9 and 7 is the least missing odd integer, hence the next term is 7. MATHEMATICA Table[ -1+ 2 3^Floor[k/2]+2 Mod[k, 2], {k, 0, 36}] LinearRecurrence[{-1, 3, 3}, {1, 3, 5}, 40] (* Harvey P. Dale, Jul 14 2018 *) CROSSREFS Cf. A048473, A062548. Sequence in context: A001259 A248370 A087126 * A125739 A219461 A122853 Adjacent sequences:  A062544 A062545 A062546 * A062548 A062549 A062550 KEYWORD nonn,changed AUTHOR Wouter Meeussen, Jun 26 2001 STATUS approved

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Last modified December 13 03:41 EST 2019. Contains 329968 sequences. (Running on oeis4.)