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 A079100 #17 Jul 21 2025 21:41:10 %S A079100 1,0,0,0,1,1,0,2,0,0,0,1,2,1,3,3,2,3,3,2,2,2,2,3,3,4,1,3,5,4,5,5,6,6, %T A079100 5,5,8,4,7,9,5,11,5,5,11,11,9,12,11,12,11,9,14,17,10,11,6,15,10,20,8, %U A079100 9,9,6,10,15,14,17,13,10,12,11,15,15,17,12,18,15,19,13,29,16,8,14,20,16,16,32,20,16,23 %N A079100 Number of 1's in n# (n primorial) = 1's in A002110(n). %H A079100 Alois P. Heinz, <a href="/A079100/b079100.txt">Table of n, a(n) for n = 0..10000</a> (999 terms from Vincenzo Librandi) %t A079100 DigitCount[#, 10, 1]&/@Rest[FoldList[Times, 1, Prime[Range[100]]]] (* _Vincenzo Librandi_, Apr 07 2014 *) %o A079100 (PARI) \\ See program in A079099. %Y A079100 Cf. A002110. A079099. %K A079100 nonn,base,easy %O A079100 0,8 %A A079100 _Cino Hilliard_, Feb 03 2003 %E A079100 Offset corrected and a(0) added by _Alois P. Heinz_, Jul 21 2025