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 A320698 #11 Oct 22 2018 12:41:33
%S A320698 3,5,6,7,9,10,11,12,14,17,18,19,20,21,22,23,24,25,27,28,31,34,36,38,
%T A320698 40,41,42,44,46,48,49,50,53,54,56,57,59,62,63,67,68,72,76,80,81,82,83,
%U A320698 84,88,92,96,97,98,100,103,106,108,109,112,114,115,118,121,124
%N A320698 Numbers whose product of prime indices is a prime power (A246655).
%C A320698 A prime index of n is a number m such that prime(m) divides n. The multiset of prime indices of n is row n of A112798.
%C A320698 Also numbers whose prime indices are all powers of a common prime number.
%H A320698 <a href="/index/Pri#prime_indices">Index entries for sequences computed from indices in prime factorization</a>
%e A320698 The sequence of all integer partitions whose Heinz numbers belong to the sequence begins: (2), (3), (1,2), (4), (2,2), (1,3), (5), (1,1,2), (1,4), (7), (1,2,2), (8), (1,1,3), (2,4), (1,5), (9), (1,1,1,2), (3,3), (2,2,2), (1,1,4), (11), (1,7), (1,1,2,2), (1,8), (1,1,1,3), (13), (1,2,4), (1,1,5), (1,9), (1,1,1,1,2), (4,4), (1,3,3), (16), (1,2,2,2), (1,1,1,4), (2,8).
%t A320698 Select[Range[100],PrimePowerQ[Times@@Cases[FactorInteger[#],{p_,k_}:>PrimePi[p]^k]]&]
%o A320698 (PARI) is(n) = my(f=factor(n)[, 1]~, p=1); for(k=1, #f, p=p*primepi(f[k])); isprimepower(p) \\ _Felix Fröhlich_, Oct 20 2018
%Y A320698 Cf. A000720, A000961, A001597, A003963, A047968, A056239, A064573, A112798, A246547, A246655, A279787, A320322, A320325, A320699, A320700.
%K A320698 nonn
%O A320698 1,1
%A A320698 _Gus Wiseman_, Oct 19 2018