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 A073818 #17 Apr 26 2024 05:18:26
%S A073818 2,4,6,10,15,22,33,44,55,68,85,102,119,145,174,203,232,261,296,333,
%T A073818 370,410,451,492,533,590,649,708,767,826,885,944,1005,1072,1139,1207,
%U A073818 1278,1358,1455,1552,1649,1746,1843,1940,2037,2134,2231,2328,2425,2540,2667
%N A073818 a(n) = max(prime(i)*(n+1-i) | 1 <= i <= n).
%C A073818 Smallest m such that m! is divisible by product_{k=0..n} A002110(k).
%C A073818 Conjecture: define an operator P(n) which when applied to a sequence s(1),s(2),s(3),... leaves s(1),...,s(n) fixed and 1) sorts in descending order if n is prime; or 2) sorts in ascending order if n is not prime every n consecutive terms thereafter. Apply P(2) to 1,2,3,... to get PS(2), then apply P(3) to PS(2) to get PS(3), then apply P(4) to PS(3), etc. The limit of PS(n) is b(n). Let c(n) = b(A000040(n) + 1), then a(n) = c(n-1) for n > 1 with a single exception at n = 5. - _Mikhail Kurkov_, May 11 2022
%e A073818 For n = 5, we take the first 5 primes in ascending order and multiply them by the numbers from 5 to 1 in descending order: 2*5 = 10 3*4 = 12 5*3 = 15 7*2 = 14 11*1 = 11. The largest product is 15, so a(5) = 15.
%o A073818 (PARI) a(n) = {ret = 0; for (i=1, n, ret = max (ret, prime(i)*(n+1-i));); return (ret);} \\ _Michel Marcus_, Jun 16 2013
%Y A073818 Cf. A073819, A073820.
%K A073818 easy,nonn
%O A073818 1,1
%A A073818 _David Wasserman_, Aug 13 2002
%E A073818 Thanks to _Naohiro Nomoto_ for correcting an editing error, Jun 01 2003