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 A167450 #4 Apr 04 2015 21:34:04 %S A167450 2,8,9,10,11,88,880,900,901,902,903,904,905,906,907,909,910,911,912, %T A167450 913,914,915,916,917,919,920,921,922,923,924,925,926,8000,9000,9001, %U A167450 9002,9003,9004,9005,9006,9007,9009,9010,9011,9012,9013,9014,9015,9016,9017 %N A167450 Smallest sequence which lists the position of digits "8" in the sequence. %C A167450 The lexicographically earliest sequence such that a(1),a(2),a(3),... is the (increasing) list of the positions of digits "8" in the string obtained by concatenating all these terms, written in base 10. %e A167450 We cannot have a(1)=1 (since then there's no "8" in the first place), but a(1)=2 is possible. %e A167450 This implies that a(2) must start with a digit "8", so a(2)=8 is the smallest possible choice. %e A167450 This allows us to go on with a(3)=9, a(4)=10, a(5)=11, but then must be follow 4 digits "8" (the 8th through 11th digit of the sequence), so a(6)=88 and a(7)=880 are the smallest possible choices. %e A167450 Then the reasoning continues in analogy with A167452-A167457. %o A167450 (PARI) concat([ [2,8,9,10,11,88,880], vector((88-11-1)\3,i,900-(i<=8)+i+(i>=18)), [8000], select(x->x%10-8 & x\10%10-8,vector((880-88)\4,i,9000-1+i)) ]) %Y A167450 Cf. A098645, A167519, A167520, A167451 - A167457. %K A167450 base,nonn %O A167450 1,1 %A A167450 _M. F. Hasler_, Nov 19 2009