# Greetings from The On-Line Encyclopedia of Integer Sequences! http://oeis.org/ Search: id:a335589 Showing 1-1 of 1 %I A335589 #11 Jan 28 2021 21:27:45 %S A335589 1,9,2,6,8,6,6,4,6,8,0,7,1,6,0,9,3,7,9,6,5,8,7,1,8,0,1,8,1,3,7,7,7,2, %T A335589 5,5,0,4,5,7,1,8,5,5,7,9,6,6,9,0,6,0,1,5,9,9,9,1,3,9,2,9,9,0,1,8,8,4, %U A335589 2,4,4,3,0,3,9,2,8,9,9,9,9,3,8,4,6,7,1,3,5,6,2,6,4,8,5,1,8,4,7,0,8,1,1,9,8 %N A335589 Decimal expansion of the sum of the reciprocals of the squares of composite numbers. %C A335589 This constant is A275647 (which gives the sum of the reciprocals of the squares of nonprime numbers) minus 1. %F A335589 Equals Sum_{k>=1} 1/A002808(k)^2. %e A335589 Equals 1/4^2 + 1/6^2 + 1/8^2 + 1/9^2 + 1/10^2 + ... = 0.19268664680716093796587180181377725504571855796690... %Y A335589 Cf. A275647. %K A335589 nonn,cons %O A335589 0,2 %A A335589 _Jon E. Schoenfield_, Jan 26 2021 # Content is available under The OEIS End-User License Agreement: http://oeis.org/LICENSE