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 A048547 #22 Feb 16 2025 08:32:40 %S A048547 9,31,890,2234,14131,30331,173031,969520,9958890,31617890,360542549, %T A048547 547631234,3316547890,17318486343,114017542334,356363452109, %U A048547 3065925634968,9995498986343,44045425415132,173193446755643,1414213562370264,4471015432706534,31575306806579083,171463720944111031,141138230008594765 %N A048547 a(n) is the smallest value of m such that A002378(m), the m-th oblong number, contains exactly n 9's. %H A048547 Eric Weisstein's World of Mathematics, <a href="https://mathworld.wolfram.com/PronicNumber.html">Pronic Number</a> %e A048547 From _Jesse Sealand_, Oct 07 2019: (Start) %e A048547 a(1) = 9 since A002378(9) = 90; %e A048547 a(2) = 31 since A002378(31) = 992; %e A048547 a(3) = 890 since A002378(890) = 792990; %e A048547 a(4) = 2234 since A002378(2234) = 4992990, etc. %e A048547 (End). %Y A048547 Cf. A048548, A002378. %Y A048547 Cf. A048529, A048531, A048533, A048535, A048537, A048539, A048541, A048543, A048545. %K A048547 nonn,base %O A048547 1,1 %A A048547 _Patrick De Geest_, May 15 1999 %E A048547 a(13)-a(16) from _Lars Blomberg_, Jun 10 2011 %E A048547 Name edited by _Jesse Sealand_, Oct 07 2019 %E A048547 a(17) from _Giovanni Resta_, Oct 09 2019 %E A048547 a(18)-a(25) from _Max Alekseyev_, Jul 25 2024