cp's OEIS Frontend

A345202 Decimal expansion of gamma + zeta(2), where gamma is Euler's constant (A001620).

%I A345202 #5 Jun 10 2021 22:36:17
%S A345202 2,2,2,2,1,4,9,7,3,1,7,4,9,7,5,9,2,9,7,0,7,8,9,2,7,2,5,6,7,2,8,4,2,7,
%T A345202 6,2,0,2,6,1,1,0,9,2,3,7,1,4,6,7,2,2,0,3,6,5,4,1,3,2,5,4,6,4,2,5,4,8,
%U A345202 7,5,1,9,7,1,8,0,8,6,5,5,4,4,7,7,0,5,7
%N A345202 Decimal expansion of gamma + zeta(2), where gamma is Euler's constant (A001620).
%C A345202 The value of the sum (see the Formula section) discovered in 1926 by the Italian mathematician and historian of science Giovanni Enrico Eugenio Vacca (1872-1953).
%D A345202 G. Vacca, Nuova serie per la costante di Eulero, C=0,577..., Rendiconti, Accademia Nazionale dei Lincei, Roma, Classe di Scienze Fisiche, Matematiche e Naturali, Serie 6, Vol. 3 (1926), pp. 19-20.
%H A345202 Ettore Carruccio, <a href="http://www.bdim.eu/item?id=BUMI_1953_3_8_4_448_0">Giovanni Vacca, matematico, storico e filosofo della scienza</a>, Bollettino dell'Unione Matematica Italiana, Serie 3, Vol. 8 (1953), pp. 448-456.
%H A345202 Tanguy Rivoal, <a href="https://hal.archives-ouvertes.fr/hal-01619235/">Is Euler's constant a value of an arithmetic special function?</a>, 2017.
%F A345202 Equals Sum_{k>=1} (1/floor(sqrt(k))^2 - 1/k) (Vacca, 1926).
%F A345202 Equals Sum_{k>=1} f(k)/k^2, where f(k) = Sum_{j=1..2*k} j/(j + k^2).
%F A345202 Equals A001620 + A013661.
%e A345202 2.22214973174975929707892725672842762026110923714672...
%t A345202 RealDigits[EulerGamma + Pi^2/6, 10, 100][[1]]
%Y A345202 Cf. A001620, A013661, A048760.
%K A345202 nonn,cons
%O A345202 1,1
%A A345202 _Amiram Eldar_, Jun 10 2021