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 A079135 #13 Jul 21 2025 21:40:46 %S A079135 0,0,0,0,0,0,0,0,0,1,0,0,2,1,2,1,3,2,3,3,2,2,5,4,5,5,3,2,6,9,4,3,10,7, %T A079135 2,4,2,13,2,5,4,6,9,6,6,9,7,10,9,11,10,8,5,5,7,6,10,16,10,14,12,14,10, %U A079135 16,13,10,12,14,13,16,17,13,20,14,11,12,8,10,15,17,9,16,15,26,21,18,19,20,28,20,12 %N A079135 Number of 7's in n# (n primorial) = 7's in A002110(n). %H A079135 Alois P. Heinz, <a href="/A079135/b079135.txt">Table of n, a(n) for n = 0..10000</a> (999 terms from Vincenzo Librandi) %t A079135 DigitCount[#, 10, 7]&/@Rest[FoldList[Times, 1, Prime[Range[100]]]] (* _Vincenzo Librandi_, Apr 07 2014 *) %o A079135 (PARI) \\ See program in A079099. %Y A079135 Cf. A002110, A079099. %K A079135 nonn,base,easy %O A079135 0,13 %A A079135 _Cino Hilliard_, Feb 03 2003 %E A079135 Offset corrected by _Alois P. Heinz_, Jul 21 2025