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 A138207 #18 Jun 23 2025 14:41:15 %S A138207 510510,965009045,30989984674,1673602584618,66298619667606 %N A138207 a(n) is the first term in a chain of at least n consecutive numbers each with exactly 7 distinct prime factors. %C A138207 a(5) > 10^13. %C A138207 a(6) > 2 * 10^15. - _Toshitaka Suzuki_, Jun 23 2025 %H A138207 Roger B. Eggleton and James A. MacDougall, <a href="http://www.jstor.org/stable/27643119">Consecutive integers with equally many principal divisors</a>, Math. Mag. 81 (2008), 235-248. [_T. D. Noe_, Oct 13 2008] %Y A138207 Cf. A087977, A087978, A138206, A154573. %K A138207 nonn,more %O A138207 1,1 %A A138207 _Donovan Johnson_, Mar 06 2008 %E A138207 a(4) from _Donovan Johnson_, Jan 15 2009 %E A138207 a(5) from _Toshitaka Suzuki_, Apr 06 2025