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 A095418 #23 Apr 29 2022 21:43:09 %S A095418 -1,0,10,0,10,20,30,17,32,26,34,35,49,53,42,51,43,74,0,56,95,77,0,81, %T A095418 38,94,97,106,104,80,109,123,108,96,97,132,100,65,145,136,141,184,145, %U A095418 173,123,99,139,172,196,120,170,176,179,213,161,169,122,201,217,184,211,216 %N A095418 Excess of sum of all decimal digits of distinct prime factors for n-th repunit over corresponding digit-sum for repunit itself (which is n). %H A095418 Max Alekseyev, <a href="/A095418/b095418.txt">Table of n, a(n) for n = 1..352</a> (first 322 terms from Giovanni Resta) %F A095418 a(n) = A095402(A002275(n)) - n = A095417(n) - n. %e A095418 n=60: concatenated distinct-prime factor-set for 60th-repunit is: %e A095418 371113313741611012112412712161354190919901279612906161418890139526741, %e A095418 its digit sum is 244, so a(60) = 244 - 60 = 184. %e A095418 The value of this excess-sum is zero if n=2,4,19,23. %t A095418 a[1] = -1; a[n_] := Total@ Flatten[IntegerDigits /@ First /@ FactorInteger[(10^n - 1)/9]] - n; Array[a, 62] (* _Giovanni Resta_, Jul 19 2018 *) %Y A095418 Cf. A095402, A002275, A095370, A095413, A095414, A095415, A095416, A095417. %K A095418 sign,base %O A095418 1,3 %A A095418 _Labos Elemer_, Jun 22 2004 %E A095418 Data corrected by _Giovanni Resta_, Jul 19 2018