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 A081253 Numbers n such that A081252(m)/m^2 has a local minimum for m = n. 10
 2, 4, 9, 18, 37, 74, 149, 298, 597, 1194, 2389, 4778, 9557, 19114, 38229, 76458, 152917, 305834, 611669, 1223338, 2446677, 4893354, 9786709, 19573418, 39146837, 78293674, 156587349, 313174698, 626349397, 1252698794, 2505397589 (list; graph; refs; listen; history; text; internal format)
 OFFSET 1,1 COMMENTS The limit of the local minima, lim A081252(n)/n^2 = 1/14. For local maxima cf. A081254. LINKS Klaus Brockhaus, Illustration for A053646, A081252, A081253 and A081254 Index entries for linear recurrences with constant coefficients, signature (2,1,-2). FORMULA a(n) = floor(2^n*7/3) a(n) = a(n-2) + 7*2^(n-2) for n > 1; a(n+2) - a(n) = A005009(n); a(n+1) - a(n) = A062092(n). G.f.: -(x^2 - 2)/((x - 1)*(x + 1)*(2*x - 1)). a(n) = 2*a(n-1) for even n, otherwise a(n) = 2*a(n-1)+1, with a(1)=2. [Bruno Berselli, Jun 19 2014] EXAMPLE 9 is a term since A081252(8)/8^2 = 5/64 = 0.078, A081252(9)/9^2 = 6/81 = 0.074, A081252(10)/10^2 = 8/100 = 0.080. CROSSREFS Cf. A053646, A081252, A081254, A005009, A062092. Sequence in context: A056185 A152537 A182028 * A118255 A206927 A019299 Adjacent sequences:  A081250 A081251 A081252 * A081254 A081255 A081256 KEYWORD nonn,easy AUTHOR Klaus Brockhaus, Mar 17 2003 STATUS approved

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Last modified October 14 00:26 EDT 2019. Contains 327991 sequences. (Running on oeis4.)