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 A350005 #8 Dec 12 2021 20:29:22 %S A350005 1,1,1,71,6392047 %N A350005 a(n) is the smallest number that starts an arithmetic progression of n consecutive ludic numbers (A003309), or 0 if no such number exists. %C A350005 a(n) is the smallest ludic number A003309(k), such that A260723(k) = A260723(k+1) = ... = A260723(k+n-2). %C A350005 a(6) > 10^8 (unless a(6) = 0). %e A350005 The first arithmetic progression of 3 consecutive ludic numbers is (1, 2, 3), so a(3) = 1. %e A350005 The first arithmetic progression of 4 consecutive ludic numbers is (71, 77, 83, 89), so a(4) = 71. %e A350005 The first arithmetic progression of 5 consecutive ludic numbers is (6392047, 6392077, 6392107, 6392137, 6392167), so a(5) = 6392047. %Y A350005 From n = 3, first row of A350007. %Y A350005 Cf. A003309, A260723. %Y A350005 Counterparts for other sequences than ludic numbers: A006560 (primes), A228433 (abundant numbers), A231623 (deficient numbers), A276821 (Sophie Germain primes), A330362 (lucky numbers). %K A350005 nonn,more %O A350005 1,4 %A A350005 _Pontus von Brömssen_, Dec 08 2021