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 A055476 #19 Jul 02 2025 16:01:59 %S A055476 1,20,400,13000,310000,11200000,224000000,10030000000,201100000000, %T A055476 4022000000000,130440000000000,3114300000000000,112341000000000000, %U A055476 2302320000000000000,101101400000000000000,2022033000000000000000 %N A055476 Powers of ten written in base 5. %C A055476 The leading numbers free of the trailing end 0's in the entries of sequence a(n) are the corresponding powers of 2 written in base 5, i.e., A000866(n). - _Lekraj Beedassy_, Oct 26 2010 %C A055476 The first formula follows from the fact that the quinary representation of 10^n - 1 is equal to the concatenation of the quinary representation of 2^n - 1 with four times the n-th repunit; so the successor 10^n is the concatenation of 2^n with n zeros. See the Regan link. - _Washington Bomfim_, Dec 24 2010 %H A055476 Rick Regan, <a href="http://www.exploringbinary.com/nines-in-quinary/">Nines in quinary</a> %F A055476 a(n) = A000866(n) followed by n zeros. %t A055476 FromDigits[IntegerDigits[#,5]]&/@(10^Range[0,20]) (* _Harvey P. Dale_, Feb 03 2019 *) %Y A055476 Cf. A000468, A011557. %K A055476 base,easy,nonn %O A055476 0,2 %A A055476 _Henry Bottomley_, Jun 27 2000 %E A055476 More terms from _James Sellers_, Jul 04 2000