OFFSET
1,3
LINKS
FORMULA
a(n+1) = n + 2^A099396(n).
G.f.: x/(1-x)^2 + x/(1-x) * Sum[k>=0, 2^k*x^(3*2^k)].
a(1) = 0, a(2) = 1, a(3) = 2, a(4) = 3, a(2^(m+1) + 2^m + k + 2) = 2^(m+2) + 2^m + k, m >= 0, 0 <= k < (2^(m+1) + 2^m). - Yosu Yurramendi, Aug 08 2016
MATHEMATICA
Join[{0, 1, 2, 3}, Select[Range[4, 100], Take[IntegerDigits[#, 2], 3]!={1, 0, 0}&]] (* Harvey P. Dale, Feb 02 2015 *)
CROSSREFS
KEYWORD
nonn,easy,base
AUTHOR
STATUS
approved