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 A377457 #8 Oct 29 2024 12:33:16
%S A377457 1,12563307224,15897851550,30412355999,37706988600,52576459775,
%T A377457 67673545631,118533901904,244316235000,297265003100,332110595000,
%U A377457 340800265728,349358409503,375624917760,378624889440,416375389115,450026519903,561162864248,596004199840,728643460544
%N A377457 Numbers k such that k and k+1 are both terms in A377386.
%H A377457 Amiram Eldar, <a href="/A377457/b377457.txt">Table of n, a(n) for n = 1..39</a>
%e A377457 12563307224 is a term since both 12563307224 and 12563307225 are in A377386: 12563307224/A034968(12563307224) = 369509036, 369509036/A034968(369509036) = 9723922 and 9723922/A034968(9723922) = 373997 are integers, and 12563307225/A034968(12563307225) = 358951635, 358951635/A034968(358951635) = 7976703 and 7976703/A034968(7976703) = 257313 are integers.
%o A377457 (PARI) fdigsum(n) = {my(k = n, m = 2, r, s = 0); while([k, r] = divrem(k, m); k != 0 || r != 0, s += r; m++); s;}
%o A377457 is1(k) = {my(f = fdigsum(k), f2, m); if(k % f, return(0)); m = k/f; f2 = fdigsum(m); !(m % f2) && !((m/f2) % fdigsum(m/f2));}
%o A377457 lista(kmax) = {my(q1 = is1(1), q2); for(k = 2, kmax, q2 = is1(k); if(q1 && q2, print1(k-1, ", ")); q1 = q2);}
%Y A377457 Cf. A034968.
%Y A377457 Subsequence of A118363, A328205, A377385, A377386 and A377455.
%Y A377457 Analogous sequences: A376795 (binary), A377272 (Zeckendorf).
%K A377457 nonn,base
%O A377457 1,2
%A A377457 _Amiram Eldar_, Oct 29 2024