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 A060881 n-th primorial (A002110) + prime(n + 1). 2
 3, 5, 11, 37, 221, 2323, 30047, 510529, 9699713, 223092899, 6469693261, 200560490167, 7420738134851, 304250263527253, 13082761331670077, 614889782588491463, 32589158477190044789, 1922760350154212639131 (list; graph; refs; listen; history; text; internal format)
 OFFSET 0,1 COMMENTS Terms are pairwise coprime with very high probability. I didn't find terms which are pairwise noncoprime, although it may be a case of the "strong law of small numbers." - Daniel Forgues, Apr 23 2012 All numbers in the range [primorial(n)+2, a(n)-1] are guaranteed to be a multiple of a prime p whose index is <= n. There are prime(n+1)-2 = A040976(n+1) such numbers. - Jamie Morken and Michel Marcus, Feb 01 2018 LINKS Harry J. Smith, Table of n, a(n) for n = 0..100 Eric Weisstein's World of Mathematics, Prime Gaps FORMULA a(n) = A002110(n) + A000040(n+1). - Michel Marcus, Feb 01 2018 EXAMPLE a(2) = 2*3 + 5 = 11. MAPLE a:= n-> mul(ithprime(k), k=1..n)+ithprime(n+1): seq(a(n), n=0..20);  # Muniru A Asiru, Feb 01 2018 MATHEMATICA Module[{nn=20, pr}, pr=Prime[Range[nn+1]]; Join[{3}, FoldList[ Times, Most[ pr]] + Rest[pr]]] (* Harvey P. Dale, Feb 19 2016 *) Total /@ Fold[Append[#1, {Prime[#2] #1[[-1, 1]], Prime[#2 + 1]}] &, {{1, 2}}, Range@ 17] (* Michael De Vlieger, Feb 21 2018 *) PROG (PARI) { n=-1; m=1; forprime (p=2, prime(101), write("b060881.txt", n++, " ", m + p); m*=p; ) } \\ Harry J. Smith, Jul 19 2009 (PARI) a(n) = prod(i=1, n, prime(i)) + prime(n+1); \\ Michel Marcus, Feb 01 2018 CROSSREFS Cf. A000040, A002110, A060882, A006862, A057588. Sequence in context: A082856 A307140 A254402 * A035345 A254401 A174915 Adjacent sequences:  A060878 A060879 A060880 * A060882 A060883 A060884 KEYWORD nonn AUTHOR N. J. A. Sloane, May 05 2001 EXTENSIONS Name changed by David A. Corneth, Mar 25 2018 STATUS approved

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Last modified September 24 05:29 EDT 2021. Contains 347623 sequences. (Running on oeis4.)