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 A376419 #10 Nov 19 2024 17:24:21 %S A376419 -1,0,4,94,284,9398,50692,2354158,75006408,445719928,53055577416, %T A376419 1055507209474,16217635288124,1663779309692618,115680647722172136, %U A376419 5515487010932110572,76943944440184239772,17660133817084175986164,686773689508904350332526,19312334585726976150166616,5276558856319725444255594528,245447734128317092747434820766 %N A376419 a(n) = prime(1+n)*A024451(n-1) - A024451(n), where A024451(n) is the numerator of Sum_{i = 1..n} 1/prime(i). %C A376419 Note that for n > 1, A070826(n) < A024451(n) < A070826(1+n) and A070826(1+n) = prime(1+n)*A070826(n). %H A376419 Antti Karttunen, <a href="/A376419/b376419.txt">Table of n, a(n) for n = 1..350</a> %H A376419 <a href="/index/Pri#primorial_numbers">Index entries for sequences related to primorial numbers</a> %o A376419 (PARI) %o A376419 A024451(n) = numerator(sum(i=1, n, 1/prime(i))); \\ From A024451 %o A376419 A376419(n) = ((prime(1+n)*A024451(n-1)) - A024451(n)); %Y A376419 Cf. A000040, A024451, A070826, A077011. %K A376419 sign %O A376419 1,3 %A A376419 _Antti Karttunen_, Nov 18 2024