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 A036603 #24 Jul 30 2025 09:44:37 %S A036603 1,1,10,110,11000,1111000,1011010000,1001110110000,1001110110000000, %T A036603 1011000100110000000,1101110101111100000000, %U A036603 10011000010001010100000000,11100100011001111110000000000,101110011001010001100110000000000,1010001001100001110110010100000000000 %N A036603 a(n) = n! in binary. %D A036603 Donald E. Knuth, Art of Computer Programming, Vol. 3, Sect. 5.3.1, Table 1. %H A036603 Alois P. Heinz, <a href="/A036603/b036603.txt">Table of n, a(n) for n = 0..167</a> %H A036603 <a href="/index/Fa#factorial">Index entries for sequences related to factorial numbers</a>. %t A036603 FromDigits/@(IntegerDigits[#, 2]&/@(Range[0, 15]!)) (* _Harvey P. Dale_, Feb 05 2012 *) %t A036603 BaseForm[Range[0, 15]!, 2] (* _Alonso del Arte_, May 19 2017 *) %o A036603 (PARI) a(n) = fromdigits(binary(n!), 10); \\ _Michel Marcus_, Jul 30 2025 %Y A036603 Cf. A000142, A049606. %K A036603 nonn,easy,base %O A036603 0,3 %A A036603 _N. J. A. Sloane_