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 A146087 #11 Dec 10 2018 02:50:19
%S A146087 2,11,20,83,92,101,164,173,182,731,740,749,812,821,830,893,902,911,
%T A146087 1460,1469,1478,1541,1550,1559,1622,1631,1640,6563,6572,6581,6644,
%U A146087 6653,6662,6725,6734,6743,7292,7301,7310,7373,7382,7391,7454,7463,7472,8021,8030,8039,8102,8111,8120
%N A146087 a(n) = 3*A146085(n) - 1.
%C A146087 Positive integers such that for every integer m==8 (mod 9) there exists a unique representation of m as a sum of the form a(l)+3a(s).
%t A146087 fQ[n_] := Module[{d = Reverse[IntegerDigits[n, 3]], k = 3, ans = True}, While[k <= Length[d], If[d[[k]] > 0, ans = False]; k += 2]; ans && d[[1]] == 1]; aQ[n_] := Mod[n + 1, 3] == 0 && fQ[(n + 1)/3]; Select[Range[10000], aQ] (* _Amiram Eldar_, Dec 09 2018 *)
%o A146087 (PARI) isa(n) = {my(d=Vecrev(digits(n, 3)), k=3); while (k <= #d, if (d[k], return (0)); k += 2;); d[1] == 1;} \\ A146085
%o A146087 isok(n) = !((n+1) % 3) && isa((n+1)/3); \\ _Michel Marcus_, Dec 09 2018
%Y A146087 Cf. A146085, A145812, A145818.
%K A146087 nonn
%O A146087 1,1
%A A146087 _Vladimir Shevelev_, Oct 27 2008
%E A146087 More terms from _Michel Marcus_, Dec 09 2018