This is a front-end for the Online Encyclopedia of Integer Sequences, made by Christian Perfect. The idea is to provide OEIS entries in non-ancient HTML, and then to think about how they're presented visually. The source code is on GitHub.
%I A060881 #77 Feb 16 2025 08:32:44
%S A060881 3,5,11,37,221,2323,30047,510529,9699713,223092899,6469693261,
%T A060881 200560490167,7420738134851,304250263527253,13082761331670077,
%U A060881 614889782588491463,32589158477190044789,1922760350154212639131
%N A060881 n-th primorial (A002110) + prime(n + 1).
%C A060881 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
%C A060881 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
%H A060881 Harry J. Smith, <a href="/A060881/b060881.txt">Table of n, a(n) for n = 0..100</a>
%H A060881 Hisanori Mishima, <a href="http://www.asahi-net.or.jp/~KC2H-MSM/mathland/matha1/index.htm">WIFC (World Integer Factorization Center)</a>: <a href="http://www.asahi-net.or.jp/~KC2H-MSM/mathland/matha1/matha106.htm">PI Pn + NextPrime (n = 1 to 100)</a>, <a href="http://www.asahi-net.or.jp/~KC2H-MSM/mathland/matha1/matha107.htm">PI Pn - NextPrime (n = 1 to 100)</a>, <a href="http://www.asahi-net.or.jp/~KC2H-MSM/mathland/matha1/matha102.htm">PI Pn + 1 (n = 1 to 100)</a>, <a href="http://www.asahi-net.or.jp/~KC2H-MSM/mathland/matha1/matha103.htm">PI Pn - 1 (n = 1 to 100)</a>.
%H A060881 Eric Weisstein's World of Mathematics, <a href="https://mathworld.wolfram.com/PrimeGaps.html">Prime Gaps</a>
%F A060881 a(n) = A002110(n) + A000040(n+1). - _Michel Marcus_, Feb 01 2018
%e A060881 a(2) = 2*3 + 5 = 11.
%p A060881 a:= n-> mul(ithprime(k), k=1..n)+ithprime(n+1): seq(a(n), n=0..20); # _Muniru A Asiru_, Feb 01 2018
%t A060881 Module[{nn=20,pr},pr=Prime[Range[nn+1]];Join[{3},FoldList[ Times,Most[ pr]] + Rest[pr]]] (* _Harvey P. Dale_, Feb 19 2016 *)
%t A060881 Total /@ Fold[Append[#1, {Prime[#2] #1[[-1, 1]], Prime[#2 + 1]}] &, {{1, 2}}, Range@ 17] (* _Michael De Vlieger_, Feb 21 2018 *)
%o A060881 (PARI) { n=-1; m=1; forprime (p=2, prime(101), write("b060881.txt", n++, " ", m + p); m*=p; ) } \\ _Harry J. Smith_, Jul 19 2009
%o A060881 (PARI) a(n) = prod(i=1, n, prime(i)) + prime(n+1); \\ _Michel Marcus_, Feb 01 2018
%Y A060881 Cf. A000040, A002110, A060882, A006862, A057588.
%K A060881 nonn
%O A060881 0,1
%A A060881 _N. J. A. Sloane_, May 05 2001
%E A060881 Name changed by _David A. Corneth_, Mar 25 2018