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 A387079 #8 Aug 19 2025 02:36:29
%S A387079 1,2,2,2,3,3,2,2,2,2,7,3,2,2,2,3,5,5,2,2,2,2,2,11,3,3,2,2,2,2,19,3,2,
%T A387079 2,2,2,2,2,2,2,5,3,3,13,5,2,2,2,7,3,3,17,2,2,2,2,31,3,2,2,2,2,2,2,2,2,
%U A387079 2,2,2,5,3,3,23,2,2,47,3,2,2,2,2,2,2,2,2
%N A387079 Least prime factor of A386482(n).
%C A387079 Minimum absolute difference |s(n-1)-s(n)|, since GCD(s(n-1),s(n)) > 1, where s = A386482.
%H A387079 Michael De Vlieger, <a href="/A387079/b387079.txt">Table of n, a(n) for n = 1..10000</a>
%F A387079 a(n) = A020639(A386482(n)).
%F A387079 a(n) <= |A386075(n-1)|.
%F A387079 a(m) = s(m) = A387073(i) for m = A387074(i).
%t A387079 Block[{c, j, k, p, m, nn}, nn = 120; c[_] := False; m[_] := 1; j = 2; c[1] = c[2] = True; {1, 2}~Join~Reap[Do[If[PrimePowerQ[j], Set[{p, k, m}, {#1, #1^(#2 - 1), #1^(#2 - 1)}] & @@ FactorInteger[j][[1]]; While[And[c[k*p], k != 0], k--];vIf[k == 0, k = m; While[c[k*p], k++]]; k *= p, k = j - 1; While[And[Or[c[k], CoprimeQ[j, k]], k != 1], k--]; If[k == 1, k += j; While[Or[c[k], CoprimeQ[j, k]], k++] ] ]; Sow[FactorInteger[k][[1, 1]] ]; Set[{c[k], j}, {True, k}], {n, 3, nn}]][[-1, 1]] ]
%Y A387079 Cf. A020639, A386482, A387073, A387074, A387075.
%K A387079 nonn
%O A387079 1,2
%A A387079 _Michael De Vlieger_, Aug 18 2025