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 A089287 #13 Mar 14 2025 21:06:46 %S A089287 3,31,159,355,169,314159,392705,10166,7998,9787003,28954814, %T A089287 157079632681,68250087,4349287,67757089,1002742628275,1230791, %U A089287 1307585156,14846149,1296188,1024025943,452477425,1492388104,381315143079141,989849547461,841346597336054869 %N A089287 Sum of all prime factors of floor(Pi*10^n), Pi=3.14.... %C A089287 a(n) = A001414(A011545(n)). %H A089287 Tyler Busby, <a href="/A089287/b089287.txt">Table of n, a(n) for n = 0..200</a> %e A089287 n=6: floor(Pi*10^6)=3141592=2*2*2*392699: a(6)=2+2+2+392699=392705. %t A089287 sapf[n_]:=Total[Flatten[Table[#[[1]],#[[2]]]&/@FactorInteger[n]]]; sapf/@ Floor[Pi 10^Range[0,30]] (* _Harvey P. Dale_, Nov 18 2018 *) %Y A089287 Cf. A089286, A089285, A089283, A000796. %K A089287 nonn %O A089287 0,1 %A A089287 _Reinhard Zumkeller_, Oct 30 2003 %E A089287 a(23)-a(25) from _Tyler Busby_, Mar 14 2025