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 A132821 #11 Aug 11 2020 10:00:01
%S A132821 0,1,3,7,3,4,5,6,5,3,2,0,0,5,4,9,1,9,2,4,3,1,4,7,1,7,5,4,0,8,6,2,5,4,
%T A132821 5,1,6,5,0,4,4,6,8,7,7,0,2,3,0,8,3,6,5,6,6,2,9,7,2,5,2,5,5,7,0,1,5,3,
%U A132821 1,9,1,1,3,3,8,5,0,0,8,1,0,9,3,2,2,2,8,9,1,3,7,0,7,3,9,7,9,3
%N A132821 Decimal expansion of the convergent to the sum of (1/9)^p where p ranges over the set of prime numbers.
%F A132821 Equals 8 * Sum_{k>=1} pi(k)/9^(k+1), where pi(k) = A000720(k). - _Amiram Eldar_, Aug 11 2020
%e A132821 0.0137345...
%o A132821 (PARI) /* Sum of 1/m^p for primes p */ sumnp(n,m) = { local(s=0,a,j); for(x=1,n, s+=1./m^prime(x); ); a=Vec(Str(s)); for(j=3,n, print1(eval(a[j])",") ) }
%Y A132821 Cf. A000720, A132799 (base 8), A010051 (base 10).
%K A132821 cons,nonn
%O A132821 0,3
%A A132821 _Cino Hilliard_, Nov 17 2007
%E A132821 Offset corrected _R. J. Mathar_, Jan 26 2009