This site is supported by donations to The OEIS Foundation.

 Hints (Greetings from The On-Line Encyclopedia of Integer Sequences!)
 A065516 Differences between products of 2 primes. 48
 2, 3, 1, 4, 1, 6, 1, 3, 1, 7, 1, 1, 3, 1, 7, 3, 2, 4, 2, 1, 4, 3, 4, 5, 3, 5, 3, 1, 1, 4, 2, 1, 1, 11, 5, 4, 3, 1, 2, 1, 1, 6, 4, 1, 7, 1, 1, 2, 1, 9, 3, 1, 2, 5, 3, 8, 1, 5, 2, 2, 7, 7, 1, 1, 2, 1, 3, 4, 1, 1, 2, 1, 1, 2, 5, 9, 2, 10, 2, 4, 1, 5, 3, 3, 2, 7, 4, 9, 2, 2, 4, 3, 1, 2, 1, 1, 2, 4, 5, 5, 2, 2, 3, 1, 2 (list; graph; refs; listen; history; text; internal format)
 OFFSET 1,1 COMMENTS See A215231 and A085809 for record values and where they occur: A215231(n) = a(A085809(n)). - Reinhard Zumkeller, Mar 23 2014 LINKS T. D. Noe, Table of n, a(n) for n=1..10000 D. A. Goldston, S. W. Graham, J. Pintz and C. Y. Yildirim, Small gaps between primes and almost primes, arXiv:math/0506067 [math.NT], 2005. FORMULA a(n) = A001358(n+1) - A001358(n). EXAMPLE a(6) = A001358(7) - A001358(6) = 21 - 15 = 6. MATHEMATICA Differences[Select[Range[329], PrimeOmega[#] == 2 &]] (* Arkadiusz Wesolowski, Nov 24 2011 *) PROG (PARI) {spg(m)=local(a, b); a=0; b=4; for(n=5, m, if(bigomega(n) == 2, a=n; print1(a-b", "); b=a; ))} (Haskell) a065516 n = a065516_list !! (n-1) a065516_list = zipWith (-) (tail a001358_list) a001358_list -- Reinhard Zumkeller, Mar 23 2014 CROSSREFS Cf. A001358. Cf. A239656. Sequence in context: A279820 A235791 A035426 * A280699 A214967 A195164 Adjacent sequences:  A065513 A065514 A065515 * A065517 A065518 A065519 KEYWORD easy,nonn AUTHOR Lior Manor, Nov 27 2001 EXTENSIONS More terms from Jason Earls, Jul 24 2003 STATUS approved

Lookup | Welcome | Wiki | Register | Music | Plot 2 | Demos | Index | Browse | More | WebCam
Contribute new seq. or comment | Format | Style Sheet | Transforms | Superseeker | Recent
The OEIS Community | Maintained by The OEIS Foundation Inc.

Last modified October 20 05:42 EDT 2019. Contains 328247 sequences. (Running on oeis4.)