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 A338224 #17 Jan 19 2025 01:30:18 %S A338224 1,2,3,5,7,6,11,13,17,14,19,15,23,22,21,29,31,34,37,35,33,38,41,39,43, %T A338224 46,47,55,53,42,59,61,57,62,77,85,67,74,69,91,71,66,73,95,119,82,79, %U A338224 87,83,86,93,115,89,94,133,143,111,106,97,105,101,118,187,103 %N A338224 Multiplicative with a(A246655(k)) = prime(k) for any k > 0 (where prime(k) denotes the k-th prime number). %C A338224 All terms are distinct and squarefree. %C A338224 This sequence has similarities with A160102, however some squarefree numbers do not appear here. %H A338224 Rémy Sigrist, <a href="/A338224/b338224.txt">Table of n, a(n) for n = 1..10000</a> %e A338224 a(3) = a(A246655(2)) = prime(2) = 3. %e A338224 a(4) = a(A246655(3)) = prime(3) = 5. %e A338224 a(12) = a(3) * a(4) = 3*5 = 15. %o A338224 (PARI) pk = select(v -> omega(v)==1, [1..m=64]); for (n=1, m, f=factor(n); print1 (prod(k=1, #f~, prime(setsearch(pk, f[k,1]^f[k,2])))", ")) %o A338224 (Python) %o A338224 from math import prod %o A338224 from sympy import prime, primepi, integer_nthroot, factorint %o A338224 def A338224(n): return prod(prime(sum(primepi(integer_nthroot(p**e,k)[0]) for k in range(1,(p**e).bit_length()))) for p, e in factorint(n).items()) # _Chai Wah Wu_, Jan 19 2025 %Y A338224 Cf. A005117, A160102, A246655. %K A338224 nonn,mult %O A338224 1,2 %A A338224 _Rémy Sigrist_, Jan 30 2021