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 A077477 Least positive integers not excluded by the rule that if n is present then 2n+1 and 3n+1 are not allowed. 6
 1, 2, 6, 8, 9, 10, 11, 12, 14, 15, 16, 18, 20, 22, 24, 26, 27, 30, 32, 35, 36, 38, 39, 40, 42, 44, 47, 48, 50, 51, 52, 54, 56, 57, 58, 59, 60, 62, 63, 64, 66, 68, 69, 70, 72, 74, 75, 76, 78, 80, 83, 84, 86, 87, 88, 90, 92, 93, 94, 96 (list; graph; refs; listen; history; text; internal format)
 OFFSET 1,2 COMMENTS What is the limit of a(n)/n? With 10000 terms, one gets a(n)/n -> 1.63317... - Jean-François Alcover Dec 11 2012 LINKS Reinhard Zumkeller, Table of n, a(n) for n = 1..10000 EXAMPLE a(5)=9 since 9 is not equal to 2*a(k)+1 nor 3*a(k)+1 for 1<=k<5; and since 9 is allowed to be present, then 19(=2*9+1) and 28(=3*9+1) are to be excluded. MATHEMATICA s = {1}; Do[u = Union[s, 2s + 1, 3s + 1]; c = Complement[Range[u // Last], u] // First; AppendTo[s, c], {10000}]; s (* Jean-François Alcover, Dec 11 2012 *) PROG (Haskell) import Data.List (delete) a077477 n = a077477_list !! (n-1) a077477_list = f [1..] where f (x:xs) = x : f (delete (2*x + 1) \$ delete (3*x + 1) xs) -- Reinhard Zumkeller, Sep 14 2011 CROSSREFS Cf. A002977. Sequence in context: A003610 A201776 A206476 * A095879 A342751 A120736 Adjacent sequences: A077474 A077475 A077476 * A077478 A077479 A077480 KEYWORD easy,nice,nonn AUTHOR Paul D. Hanna, Nov 08 2002 STATUS approved

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Last modified December 8 13:24 EST 2023. Contains 367679 sequences. (Running on oeis4.)