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 A081313 Numbers having more than one representation as sum of a prime and a 3-smooth number. 4
 4, 5, 6, 7, 8, 9, 10, 11, 12, 13, 14, 15, 16, 17, 18, 19, 20, 21, 22, 23, 25, 26, 27, 29, 30, 31, 32, 33, 34, 35, 37, 38, 39, 40, 41, 43, 44, 45, 46, 47, 49, 50, 51, 53, 55, 56, 57, 59, 61, 62, 63, 64, 65, 67, 68, 69, 70, 71, 73, 74, 75, 76, 77, 79, 80, 81, 82, 83, 84, 85, 86 (list; graph; refs; listen; history; text; internal format)
 OFFSET 1,1 LINKS Reinhard Zumkeller, Table of n, a(n) for n = 1..10000 FORMULA A081308(a(n)) > 1. MATHEMATICA nmax = 1000; S = Select[Range[nmax], Max[FactorInteger[#][[All, 1]]] <= 3 &]; A081308[n_] := Count[TakeWhile[S, # < n &], s_ /; PrimeQ[n - s]]; Select[Range[nmax], A081308[#] > 1 &] (* Jean-François Alcover, Oct 13 2021 *) PROG (Haskell) a081313 n = a081313_list !! (n-1) a081313_list = filter ((> 1) . a081308) [1..] -- Reinhard Zumkeller, Jul 04 2012 CROSSREFS Cf. A000040, A003586, A081308, A081312. Subsequence of A081311. Sequence in context: A171526 A171463 A020705 * A227983 A081333 A026419 Adjacent sequences: A081310 A081311 A081312 * A081314 A081315 A081316 KEYWORD nonn AUTHOR Reinhard Zumkeller, Mar 17 2003 STATUS approved

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Last modified December 6 10:23 EST 2022. Contains 358630 sequences. (Running on oeis4.)