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 A095415 #23 Apr 29 2022 21:27:04 %S A095415 2,3,5,7,9,11,13,17,19,23,27,31,47,59,67,71,83,113,127,139,163,197, %T A095415 211,229,251,263,311,317,347,421,457,461 %N A095415 Length of repunits of which the prime factor-digit-excess computed by A095414 equals 0. %C A095415 541, 701, 857 are also terms. Conjecture: Except for the number 4, A046413 is a subsequence. Conjecture: except for the prime powers 9 and 27, all terms are prime. - _Chai Wah Wu_, Nov 03 2019 %C A095415 Sequence continues as 467?, 479?, 509?, 541, 557?, 571?, 577?, 593?, 599?, 617?, 643?, 647?, 661?, 673?, 683?, 691?, 701, 727?, 743?, 751?, 757?, 769?, 773?, 821?, 857, 863?, 887?, 911?, 967?, 971?, 977?, 991?, where ? marks uncertain/candidate terms. - _Max Alekseyev_, Apr 29 2022 %F A095415 Solutions to A095414(x) = 0. %t A095415 d[1] = -1; d[n_] := Total[ IntegerLength /@ First /@ FactorInteger[(10^n - 1)/9]] - n; Select[ Range[67], d[#] == 0 &] (* _Giovanni Resta_, Jul 16 2018 *) %Y A095415 A004023 is a subsequence. %Y A095415 Cf. A002275, A004023, A095370, A095407, A095413-A095418. %K A095415 nonn,more,base %O A095415 1,1 %A A095415 _Labos Elemer_, Jun 22 2004 %E A095415 Data corrected and extended by _Giovanni Resta_, Jul 16 2018 %E A095415 a(29)-a(32) confirmed by _Max Alekseyev_, Apr 29 2022