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 A378055 #6 Nov 15 2024 13:10:45
%S A378055 638000,13466816,14753024,16092999,19494189,38137749,63668079,
%T A378055 80061344,86119704,107232255,112375899,121550624,127205000,154466675,
%U A378055 294147854,391738599,553140224,561712095,682199595,728999999,871651143,879207615,911062844,920985624,1017609999
%N A378055 Numbers k such that k | A378053(k) and (k+1) | A378053(k+1).
%t A378055 q[n_] := q[n] = And @@ Divisible[{Times @@ ((d = Divisors[n]) + 1), Times @@ (Rest@d - 1)}, n]; Select[Range[2*10^7], q[#] && q[# + 1] &]
%o A378055 (PARI) is1(k) = if(k == 1, 1, my(d = divisors(k)); !(gcd(prod(k=1, #d, d[k]+1), prod(k=2, #d, d[k]-1)) % k));
%o A378055 lista(kmax) = {my(q1 = is1(1), q2); for(k = 2, kmax, q2 = is1(k); if(q1 && q2, print1(k-1, ", ")); q1 = q2);}
%Y A378055 Intersection of A355332 and A377949.
%Y A378055 Subsequence of A378054.
%Y A378055 Cf. A020696, A377484, A378053, A378059.
%K A378055 nonn
%O A378055 1,1
%A A378055 _Amiram Eldar_, Nov 15 2024