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 A072610 #12 Jun 05 2025 09:54:57
%S A072610 3,11,29,67,69,71,179,181,189,441,1059,2699,6453,6459,6471,15927,
%T A072610 40071,40083,40121,100363,251705,251707,251709,251721,251723,251735,
%U A072610 251737,251741,251761,637233,637235,637319,637321,637323,637325,637329,637333
%N A072610 Values of transition of A072608(n) from alternating behavior (0,1,0,1,..) into steadily-1 (1,1,1,..) behavior or changing back. Expressing in terms of A072609(n): at n values it switches from steadily 0 into steadily 1 successive values or back.
%C A072610 Values of n such that A072609(n) != A072609(n+1).
%C A072610 Switching zones appear in clusters of n. Remainder A004648 either drops or starts to increase at these values of n.
%e A072610 At n=637330...637370 the change of remainder A004648 is as follows: {..637323, 4, 13, 4, 637333, 637327, 637335, 637323, 637319, 637325, 637321, 4, 11, 4, 7, 34, 29, 26, 17, 44, 43, 46, 41, 38, 49, 52, 49, 44, 37, 28, 37..}
%t A072610 mm[x_] := Mod[Mod[Prime[x], x], 2];
%t A072610 pm[x_] := mm[x]*mm[x+1];
%t A072610 Do[s1=pm[n]; s2=pm[n+1]; If[ !Equal[s1, s2], Print[n]], {n, 10^9}]
%Y A072610 Cf. A004648, A072608, A072609.
%K A072610 nonn
%O A072610 1,1
%A A072610 _Labos Elemer_, Jun 24 2002