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 A052215 #31 Jul 16 2023 02:38:16 %S A052215 2,14,230,7314,378014,11243154,965009045,65893166030,5702759516090, %T A052215 605247139068494,78971815814237709,22593106657425552170 %N A052215 a(n) = smallest number m such that m and m+1 are the product of exactly n distinct primes. %C A052215 Prime factors may not be repeated in m and m+1. The difference between this sequence and A093548 is that in the latter, prime factors may be repeated. So the present sequence imposes more stringent conditions than A093548, hence a(n) >= A093548(n). - _N. J. A. Sloane_, Nov 21 2015 %C A052215 A115186(n) <= A093548(n) <= a(n). - _Zak Seidov_, Jan 16 2015 %C A052215 2^63 < a(12) <= 22593106657425552170. [_Donovan Johnson_, Oct 23 2008] %C A052215 a(12) confirmed to be the upper limit of the range above. - _Bert Dobbelaere_, Jun 27 2019 %e A052215 14 and 15 are both the product of 2 primes. %e A052215 230 is the 3rd entry because we have (230=2*5*23, 231=3*7*11). %Y A052215 Cf. A093548 (another version), A093549, A093550, A115186, A318896. %Y A052215 Subsequence of A005117. %K A052215 hard,nice,nonn,more %O A052215 1,1 %A A052215 _Erich Friedman_, Jan 29 2000 %E A052215 More terms from _Naohiro Nomoto_, Jul 08 2001 %E A052215 a(7) from _Farideh Firoozbakht_, Apr 06 2004 %E A052215 a(8)-a(10) from _Martin Fuller_, Jan 17 2006 %E A052215 a(11) from _Donovan Johnson_, Oct 23 2008 %E A052215 a(12) from _Bert Dobbelaere_, Jun 27 2019