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 A342647 #18 Mar 18 2021 05:57:17
%S A342647 5,8,8,2,5,1,4,3,3,9,6,8,1,6,3,5,6,4,7,4,1,7,8,3,1,1,7,9,4,2,5,3,1,4,
%T A342647 3,7,2,2,8,4,7,5,7,2,7,7,6,2,5,5,9
%N A342647 Decimal expansion of Sum_{n>=1} log(cos(1/n)) * log(sin(1/n)).
%C A342647 log(cos(1/n)) ~ -1/(2*n^2) when n -> oo, so the series log(cos(1/n)) is convergent (A336603), but
%C A342647 log(sin(1/n)) ~ -log(n) when n -> oo, so the series log(sin(1/n)) is divergent.
%C A342647 However, as log(cos(1/n)) * log(sin(1/n)) ~ log(n)/(2*n^2) when n -> oo, the series log(cos(1/n)) * log(sin(1/n)) is convergent.
%D A342647 Jean-Marie Monier, Analyse, Exercices corrigés, 2ème année MP, Dunod, 1997, Exercice 3.2.1.f p. 279.
%F A342647 Equals Sum_{n>=1} log(cos(1/n)) * log(sin(1/n)).
%e A342647 0.588251433968163564741783117942531437228475727762559...
%o A342647 (PARI) sumpos(n=1, log(cos(1/n)) * log(sin(1/n))) \\ _Michel Marcus_, Mar 18 2021
%Y A342647 Cf. A336405, A336603.
%K A342647 nonn,cons,more
%O A342647 0,1
%A A342647 _Bernard Schott_, Mar 17 2021
%E A342647 a(4)-a(51) from _Jon E. Schoenfield_, Mar 18 2021