# Greetings from The On-Line Encyclopedia of Integer Sequences! http://oeis.org/ Search: id:a337225 Showing 1-1 of 1 %I A337225 #13 Aug 22 2020 18:51:15 %S A337225 1,1,1,2,2,1,2,3,3,2,2,2,4,2,3,4,4,3,3,4,4,2,3,3,6,4,4,4,6,3,4,5,5,4, %T A337225 4,6,6,4,5,6,6,4,3,4,6,3,4,4,8,6,6,8,8,4,6,6,9,6,6,6,8,4,5,6,6,5,5,8, %U A337225 8,6,7,9,9,6,5,8,10,6,7,8,8,6,5,8,6,3,5 %N A337225 a(n) is the number of distinct integers k that can be obtained by starting from the binary expansion of n and repeatedly replacing some square XX by X. %C A337225 Leading zeros in binary expansions are ignored. %C A337225 The least possible k is: %C A337225 - 0 for n = 0, %C A337225 - 1 for n = 2^m-1 for some m > 0, %C A337225 - 2 for n = 2*m for some m > 0, %C A337225 - 5 otherwise. %H A337225 Rémy Sigrist, Table of n, a(n) for n = 0..8192 %H A337225 Rémy Sigrist, PARI program for A337225 %H A337225 Index entries for sequences related to binary expansion of n %F A337225 a(2^k-1) = k for any k > 0. %e A337225 The first terms, alongside the binary expansions of n and of the corresponding k's, are: %e A337225 n a(n) bin(n) {bin(k)} %e A337225 -- ---- ------ ------------------- %e A337225 0 1 0 {0} %e A337225 1 1 1 {1} %e A337225 2 1 10 {10} %e A337225 3 2 11 {1, 11} %e A337225 4 2 100 {10, 100} %e A337225 5 1 101 {101} %e A337225 6 2 110 {10, 110} %e A337225 7 3 111 {1, 11, 111} %e A337225 8 3 1000 {10, 100, 1000} %e A337225 9 2 1001 {101, 1001} %e A337225 10 2 1010 {10, 1010} %e A337225 11 2 1011 {101, 1011} %e A337225 12 4 1100 {10, 100, 110, 1100} %e A337225 13 2 1101 {101, 1101} %e A337225 14 3 1110 {10, 110, 1110} %e A337225 15 4 1111 {1, 11, 111, 1111} %e A337225 16 4 10000 {10, 100, 1000, 10000} %o A337225 (PARI) See Links section. %Y A337225 Cf. A337222. %K A337225 nonn,base %O A337225 0,4 %A A337225 _Rémy Sigrist_, Aug 19 2020 # Content is available under The OEIS End-User License Agreement: http://oeis.org/LICENSE