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 A284748 #33 Nov 22 2024 00:35:25
%S A284748 2,2,6,8,4,3,3,3,0,9,5,0,2,0,4,8,7,2,1,3,5,6,3,2,5,4,0,1,4,4,0,5,7,6,
%T A284748 0,4,3,8,1,2,5,8,6,6,3,9,1,6,8,1,3,9,5,1,6,8,8,9,9,3,9,3,2,6,4,3,2,9,
%U A284748 0,9,7,1,5,1,0,7,6,6,6,0,2,1,6,6,2,0,1,2,4,1,1,7,6,6,7,9,1,8,1,6,7,1,0,6,2,1
%N A284748 Decimal expansion of the sum of reciprocals of composite powers.
%F A284748 Equals Sum_{n>=1} 1/A002808(n)^(n+1) = (A275647 - 1) + (A278419 - 1) + ...
%F A284748 Equals Sum_{n>=1} 1/A002808(n)*(A002808(n)-1).
%F A284748 Equals Sum_{n>=2} (Zeta(n) - PrimeZeta(n) - 1) = Sum_{n>=2} CompositeZeta(n).
%F A284748 Equals 1 - A136141.
%e A284748 Equals 1/(4*3)+1/(6*5)+1/(8*7)+1/(9*8)+1/(10*9)+...
%e A284748 = 0.226843330950204872135632540144057604...
%t A284748 RealDigits[ NSum[Zeta[n]-1-PrimeZetaP[n], {n, 2, Infinity}], 10, 105] [[1]]
%o A284748 (PARI) 1 - sumeulerrat(1/(p*(p-1))) \\ _Amiram Eldar_, Mar 18 2021
%Y A284748 Cf. A066247, A077761, A179119, A185380.
%Y A284748 Decimal expansion of the sum of reciprocal powers: A136141 (primes), A154945 (primes at even powers), A152447 (semiprimes), A154932 (squarefree semiprimes).
%Y A284748 Decimal expansion of the 'nonprime zeta function': A275647 (at 2), A278419 (at 3).
%K A284748 nonn,cons
%O A284748 0,1
%A A284748 _Terry D. Grant_, Apr 01 2017
%E A284748 More digits from _Vaclav Kotesovec_, Jan 13 2021