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 A361111 #20 Mar 03 2023 06:02:09 %S A361111 0,3,5,12,10,3,5,20,18,3,9,24,18,6,5,17,48,34,3,9,40,36,7,65,72,10,3, %T A361111 33,96,66,11,129,132,6,3,17,80,68,5,257,258,130,129,33,34,6,13,513, %U A361111 514,1026,1025,9,14,2050,2049,65,66,4098,4097,5,260,264,11,7 %N A361111 The binary expansion of a(n) specifies which primes divide A360519(n). %H A361111 Rémy Sigrist, <a href="/A361111/b361111.txt">Table of n, a(n) for n = 1..10000</a> %H A361111 Rémy Sigrist, <a href="/A361111/a361111.gp.txt">PARI program</a> %H A361111 N. J. A. Sloane, <a href="/A360519/a360519.pdf">Table showing A360519(1)-A360519(13)</a>, also the smallest missing number (smn, A361109 and A361110), binary vectors showing which terms are divisible by the primes 2, 3, 5, 7, 11; and phi, a decimal representation of those binary vectors (A361111). This sequence forms the bottom row of the table. %F A361111 a(n) = A087207(A360519(n)). - _Rémy Sigrist_, Mar 03 2023 %e A361111 A360519(6) = 12, which is divisible by 2, 3, but not 5, 7, 11, ... So we write down 1, 1, 0, 0, 0, .... Thus a(6) has binary expansion ...00011, and so a(6) = 3. %o A361111 (PARI) See Links section. %Y A361111 Cf. A087207, A360519. %K A361111 nonn,base %O A361111 1,2 %A A361111 _Scott R. Shannon_ and _N. J. A. Sloane_, Mar 03 2023 %E A361111 More terms from _Rémy Sigrist_, Mar 03 2023