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 A228066 #25 Feb 16 2025 08:33:20 %S A228066 0,3,20,120,763,5210,38042,288616,2259818,18165437,149165130, %T A228066 1246782034,10576153259,90845450184,788766653816,6912684881941, %U A228066 61079444849535,543599336199608,4869141098476425,43865568875289741,397232678533509005,3614124134441452287 %N A228066 a(n) = A006879(n) - A228065(n). %C A228066 Difference between the number of primes with n digits (A006879) and the difference of consecutive integers nearest to (10^n)/log(10^n) (see A228065). %C A228066 The sequence A006879(n) is always > A228065(n) for 1 <= n <= 28. %C A228066 The sequence (A228065) provides exactly the first value of pi(10^n)- pi(10^(n-1)) for n = 1, and yields an average relative difference in absolute value, i.e., average(abs(A228066(n))/(A006879(n))) = 0.0436296... for 1 <= n <= 28. %C A228066 Note that A057834(n) = 10^n/log(10^n) is not defined for n = 0; its value is set arbitrarily to 0. - Updated by _Eduard Roure Perdices_, Apr 18 2021 %H A228066 Eduard Roure Perdices, <a href="/A228066/b228066.txt">Table of n, a(n) for n = 1..28</a> %H A228066 Eric Weisstein's World of Mathematics, <a href="https://mathworld.wolfram.com/PrimeCountingFunction.html">Prime Counting Function</a> %F A228066 a(n) = A006879(n) - A228065(n). %Y A228066 Cf. A006880, A006879, A228065. %K A228066 nonn,base,less %O A228066 1,2 %A A228066 _Vladimir Pletser_, Aug 06 2013