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 A349305 #8 Nov 21 2021 05:06:52
%S A349305 4,10,1,19940,54584,204323,2789143044,27092041443
%N A349305 a(n) is the start of the least run of exactly n consecutive numbers with the same number of nonunitary divisors.
%C A349305 a(9) > 10^11, if it exists.
%e A349305 a(2) = 10 since A048105(10) = A048105(11) = 0, and A048105(9) != 0 and A048105(12) != 0.
%t A349305 d[n_] := DivisorSigma[0, n] - 2^PrimeNu[n]; seq[len_, nmax_] := Module[{s = Table[0, {len}], dprev = -1, n = 1, c = 0, k = 0}, While[k < len && n < nmax, d1 = d[n]; If[d1 == dprev, c++, If[c > 0 && c <= len && s[[c]] == 0, k++; s[[c]] = n - c]; c = 1]; n++; dprev = d1]; TakeWhile[s, # > 0 &]]; seq[6, 10^6]
%Y A349305 Cf. A048105, A344315.
%Y A349305 Similar sequences: A006558, A045983, A048932, A067813, A077657, A318166.
%K A349305 nonn,more
%O A349305 1,1
%A A349305 _Amiram Eldar_, Nov 14 2021