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 A096302 #16 Sep 08 2022 08:45:14 %S A096302 81,1620,24300,324000,4050000,48600000,567000000,6480000000, %T A096302 72900000000,810000000000,8910000000000,97200000000000, %U A096302 1053000000000000,11340000000000000,121500000000000000,1296000000000000000 %N A096302 Number of combinations of two natural numbers that together have n digits. %H A096302 Vincenzo Librandi, <a href="/A096302/b096302.txt">Table of n, a(n) for n = 2..100</a> %F A096302 a(n) = Sum_{i=0..n-1} binomial(n-1, i)*9^(i+1)*i. %F A096302 a(n) = 81*(n-1)*10^(n-2). - _Vladeta Jovovic_, Jun 26 2004 %t A096302 f[n_] := Sum[Binomial[n - 1, i]*9^(i + 1)*i, {i, 0, n}]; Table[ a[n], {n, 2, 17}] (* _Robert G. Wilson v_, Jun 30 2004 *) %o A096302 (Magma) [81*(n-1)*10^(n-2): n in [2..30]]; // _Vincenzo Librandi_, Jun 06 2011 %Y A096302 Cf. A053541. %K A096302 nonn,easy,base %O A096302 2,1 %A A096302 Hagai Helman (Helman(AT)actcom.net.il), Jun 25 2004 %E A096302 More terms from _Robert G. Wilson v_, Jun 30 2004