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 A358671 #15 Nov 28 2022 17:22:42
%S A358671 2,4,6,14,18,24,26,28,38,42,52,54,62,72,74,76,78,86,96,98,114,122,124,
%T A358671 126,134,146,148,158,172,186,194,206,218,222,244,254,258,268,278,292,
%U A358671 302,314,316,326,362,366,386,388,398,402,412,422,434,436,438,446,458,474,482,508,518,542,554,556,558
%N A358671 Numbers k such that for all factorizations of k as x*y, the sum x+y is carryfree when the addition is done in the primorial base, A049345.
%C A358671 Numbers k such that there are no factorization of k into such a pair of natural numbers x and y that would generate any carries when added together in the primorial base.
%H A358671 <a href="/index/Pri#primorialbase">Index entries for sequences related to primorial base</a>
%F A358671 {k | A358233(k) = A038548(k)}.
%e A358671 8 is not included, because while factorization 1*8 would yield a carry-free sum ("1" and "110" added together gives "111" = 9 in primorial base, A049345), factorization 2*4 would not, as 2+4 (= "10" + "20") and 2 is the max. allowed digit in the second rightmost place.
%o A358671 (PARI) isA358671(n) = A358670(n);
%Y A358671 Cf. A038548, A049345, A276086, A329041, A358233, A358670 (characteristic function).
%Y A358671 Cf. also A358673.
%K A358671 nonn,base
%O A358671 1,1
%A A358671 _Antti Karttunen_, Nov 26 2022