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 A031005 #8 Mar 25 2019 17:31:43 %S A031005 6,20,34,48,62,76,77,79,81,83,85,87,89,90,111,132,153,174,195,216,218, %T A031005 221,224,227,230,233,236,237,258,279,300,321,342,363,365,368,371,374, %U A031005 377,380,383,384,405,426,447,468,489,510,512 %N A031005 Position of n-th 6 in A030998. %t A031005 Flatten[Position[Flatten[IntegerDigits[#,7]&/@Range[0,200]],6]]-1 (* _Harvey P. Dale_, Mar 25 2019 *) %K A031005 nonn %O A031005 1,1 %A A031005 _Clark Kimberling_