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 A079163 #19 Jul 21 2025 21:40:42 %S A079163 0,0,0,0,0,0,0,0,4,1,2,1,0,0,0,2,2,2,3,2,5,4,3,4,1,2,2,4,7,7,4,6,6,3, %T A079163 7,4,8,7,5,11,11,8,7,14,8,8,13,10,8,5,16,6,8,10,5,14,14,14,12,15,15, %U A079163 15,11,7,12,14,13,18,15,17,10,17,13,18,14,13,16,20,16,14,17,19,19,18,22,13,19,17,17,24,23 %N A079163 Number of 9's in n# (n primorial) = 9's in A002110(n). %H A079163 Alois P. Heinz, <a href="/A079163/b079163.txt">Table of n, a(n) for n = 0..10000</a> (999 terms from Vincenzo Librandi) %t A079163 DigitCount[#, 10, 9]&/@Rest[FoldList[Times, 1, Prime[Range[90]]]] (* _Harvey P. Dale_, Dec 07 2011 *) %o A079163 (PARI) \\ See program in A079099. %Y A079163 Cf. A002110, A079099. %K A079163 nonn,base,easy %O A079163 0,9 %A A079163 _Cino Hilliard_, Feb 03 2003 %E A079163 Offset corrected by _Alois P. Heinz_, Jul 21 2025