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 A289324 #12 Mar 01 2018 07:41:12 %S A289324 -1,0,2,-4,8,56,28,-92,-1350,-2446,4658,-3174,-101402,-16318,-632474, %T A289324 -1954842,10724544,45041304,111069790,548593100,1818298480 %N A289324 Number of twos minus number of ones in the first 10^n entries of the Kolakoski sequence, A000002. %C A289324 This is equivalent to A195206, since a(n) = (#twos)-(#ones) = 10^n-2*(#ones) in the first 10^n entries of A000002. %C A289324 For example, a(2) = 51 - 49 = (100 - 49) - 49 = 100 - 2*49 = 2 because there are 49 ones and 51 twos in the first 100 = 10^2 entries of A000002. %C A289324 The entries in this sequence appear to be of order 10^(n/2), whereas the entries in A195206 are larger (of order 10^n). %C A289324 This sequence is analogous to A289323; the difference is that the indices are powers of ten instead of powers of two. %D A289324 See the references and links for A195206, A289322. %F A289324 a(n) = 10^n - 2*A195206(n). %e A289324 The first 10 entries in the Kolakoski sequence, A000002, are 1221121221. There are 5 ones and 5 twos, so a(1) = 5 - 5 = 0. %e A289324 The first 100=10^2 entries in the Kolakoski sequence A000002 include 49 ones and 51 twos, so a(2) = 51 - 49 = 2. %Y A289324 Cf. A000002, A195206, A054353, A074286, A088568, A156077. %K A289324 sign,more %O A289324 0,3 %A A289324 _Richard P. Brent_, Jul 07 2017 %E A289324 Additional (20th) term from _Richard P. Brent_, Mar 01 2018