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 A114403 3-almost prime gaps. First differences of A014612. 23
 4, 6, 2, 7, 1, 2, 12, 2, 1, 5, 2, 11, 3, 2, 2, 5, 1, 2, 14, 6, 1, 3, 3, 5, 4, 2, 1, 7, 1, 5, 8, 9, 1, 5, 1, 10, 1, 5, 1, 1, 2, 1, 7, 4, 2, 2, 5, 12, 5, 10, 8, 1, 5, 2, 4, 2, 1, 1, 9, 3, 3, 5, 2, 5, 2, 4, 3, 2, 1, 1, 4, 2, 18, 6, 2, 4, 3, 7, 1, 5, 5, 2, 9, 2, 1 (list; graph; refs; listen; history; text; internal format)
 OFFSET 1,1 LINKS T. D. Noe, Table of n, a(n) for n=1..10000 FORMULA a(n) = A014612(n+1) - A014612(n). EXAMPLE a(1) = 4 = 12-8 where 8 is the first 3-almost prime and 12 is the second. a(2) = 6 = 18-12 a(3) = 2 = 20-18 a(4) = 7 = 27-20 MAPLE is3Alm := proc(n::integer) local ifa, ex, i ; ifa := op(2, ifactors(n)) ; ex := 0 ; for i from 1 to nops(ifa) do ex := ex+ op(2, op(i, ifa)) ; od : if ex = 3 then RETURN(true) ; else RETURN(false) ; fi ; end: A014612 := proc(n::integer) local resul, i; i :=1; resul := 8 ; while i < n do resul := resul + 1 ; if is3Alm(resul) then i := i+1 ; fi ; od ; RETURN(resul) ; end: A114403 := proc(n::integer) RETURN(A014612(n+1)-A014612(n)) ; end: for n from 1 to 160 do printf("%d, ", A114403(n)) ; od: # R. J. Mathar, Apr 25 2006 MATHEMATICA Differences[Select[Range[425], PrimeOmega[#] == 3 &]] (* Jayanta Basu, Jul 01 2013 *) CROSSREFS Cf. A014612, A065516, A111870, A111871, A114403-A114411, A114412-A114422. Sequence in context: A029677 A045867 A236189 * A137662 A336049 A153124 Adjacent sequences:  A114400 A114401 A114402 * A114404 A114405 A114406 KEYWORD easy,nonn AUTHOR Jonathan Vos Post, Nov 25 2005 EXTENSIONS Corrected and extended by R. J. Mathar, Apr 25 2006 STATUS approved

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Last modified December 3 05:29 EST 2020. Contains 338899 sequences. (Running on oeis4.)