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 A048539 #19 Feb 16 2025 08:32:40 %S A048539 7,23,74,2248,2292,23506,50552,742667,2357022,22706949,74555050, %T A048539 703955648,745020507,3996943276,74333434976,244040827632,505525029504, %U A048539 5963015642907,23548897033949,156701172827632,745354652534976,758666893673274,7453694087868501,77198164845775648,505525028614365003 %N A048539 a(n) is the smallest value of m such that A002378(m), the m-th oblong number, contains exactly n 5's. %H A048539 Eric Weisstein's World of Mathematics, <a href="https://mathworld.wolfram.com/PronicNumber.html">Pronic Number</a> %Y A048539 Cf. A048540, A002378. %Y A048539 Cf. A048529, A048531, A048533, A048535, A048537, A048541, A048543, A048545, A048547. %K A048539 nonn,base %O A048539 1,1 %A A048539 _Patrick De Geest_, May 15 1999 %E A048539 a(14)-a(16) from _Lars Blomberg_, Jun 10 2011 %E A048539 a(17) added and name edited by _Giovanni Resta_, Oct 09 2019 %E A048539 a(18)-a(25) from _Max Alekseyev_, Jul 25 2024