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 A294030 #14 Jul 16 2022 07:13:58
%S A294030 1,9,14,42,161,161,798,1400,86156,123656,419430,387868,508797,772121,
%T A294030 870233,4162866,8754569,126168912,126991491,128007618,131491736
%N A294030 Values of bphi(k) = bphi(k+1), where bphi is the bi-unitary analog of Euler's totient function (A116550).
%C A294030 The bi-unitary totient function of numbers k such that k and k+1 have the same function value (A293184).
%F A294030 a(n) = A116550(A293184(n)).
%e A294030 9 is in the sequence since 9 = bphi(14) = bphi(15).
%t A294030 bphi[1] = 1; bphi[n_] := With[{pp = Power @@@ FactorInteger[n]}, Count[Range[n], m_ /; Intersection[pp, Power @@@ FactorInteger[m]] == {}]]; a={}; b1=0; Do[b2 = bphi[k]; If[b1 == b2, a = AppendTo[a, b1]]; b1 = b2, {k, 1, 10^2}]; a (* after _Jean-François Alcover_ at A116550 *)
%Y A294030 The bi-unitary version of A003275.
%Y A294030 Cf. A116550, A293184.
%K A294030 nonn,more
%O A294030 1,2
%A A294030 _Amiram Eldar_, Oct 22 2017
%E A294030 a(10)-a(11) from _Michel Marcus_, Nov 14 2017
%E A294030 a(12)-a(21) from _Amiram Eldar_, Jul 16 2022