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 A201019 #11 Jun 16 2016 17:59:21 %S A201019 23,47,61,227,281,283,347,443,449,467,487,647,683,743,769,773,797,821, %T A201019 823,829,863,887,967,977,1123,1213,1231,1283,1289,1321,1471,1481,1487, %U A201019 1489,1627,1697,1741,1783,1823,1847,1861,1873,2113,2131,2237,2243,2267,2273,2281,2287,2311 %N A201019 Primes whose multiplicative digital root is 6. %C A201019 Complement of A201020 with respect to A034053. %H A201019 Harvey P. Dale, <a href="/A201019/b201019.txt">Table of n, a(n) for n = 1..1000</a> %e A201019 Prime 227 is in sequence because 2*2*7=28, 2*8=16, 1*6=6. %t A201019 dr6Q[n_]:=NestWhile[Times@@IntegerDigits[#]&,n,#>9&]==6; Select[ Prime[ Range[ 400]],dr6Q] (* _Harvey P. Dale_, Jun 16 2016 *) %Y A201019 Cf. A201020 (composite numbers whose multiplicative digital root is 6), A034053 (numbers whose multiplicative digital root is 6). %K A201019 nonn,base %O A201019 1,1 %A A201019 _Jaroslav Krizek_, Nov 25 2011