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 A305215 #13 Oct 10 2020 05:53:38
%S A305215 1,1,2,2,6,12,8,16,48,96,48,240,480,960,960,960,3840,7680,3072,18432,
%T A305215 36864,73728,147456,147456,442368,884736,1769472,589824,4128768,
%U A305215 8257536,16515072,33030144,16515072,82575360,165150720,330301440,660602880,1321205760
%N A305215 a(n) is the number of numbers whose largest prime power factor equals A000961(n).
%C A305215 The largest prime power factor of a number n is given by A034699(n).
%F A305215 a(n) = A000005(A051451(n) / A000961(n)).
%e A305215 The first terms, alongside A000961(n) and the set of numbers k such that A034699(k) = A000961(n), are:
%e A305215 n a(n) A000961(n) S(n)
%e A305215 -- ---- ---------- ----
%e A305215 1 1 1 { 1 }
%e A305215 2 1 2 { 2 }
%e A305215 3 2 3 { 3, 6 }
%e A305215 4 2 4 { 4, 12 }
%e A305215 5 6 5 { 5, 10, 15, 20, 30, 60 }
%e A305215 6 12 7 { 7, 14, 21, 28, 35, 42, 70, 84, 105, 140, 210, 420 }
%e A305215 7 8 8 { 8, 24, 40, 56, 120, 168, 280, 840 }
%o A305215 (PARI) my(l=1); for (k=1, 103, if (omega(k) <= 1, l = lcm(l, k); print1 (numdiv(l/k) ", ")))
%Y A305215 Cf. A000005, A000961, A034699, A051451.
%Y A305215 First differences of A056795.
%Y A305215 Row lengths of A305325.
%K A305215 nonn
%O A305215 1,3
%A A305215 _Rémy Sigrist_, May 27 2018