A300558 a(n) is the concatenation n written in base 2 n times, n-1 written in base 2 n-1 times, ..., 1 written in base 2 once.

1, 10101, 11111110101, 10010010010011111110101, 10110110110110110010010010011111110101, 11011011011011011010110110110110110010010010011111110101, 11111111111111111111111011011011011011010110110110110110010010010011111110101

Offset

1,2

Links

Seiichi Manyama, Table of n, a(n) for n = 1..21

Prog

(Ruby)
def A300558(n)
  a = '1'
  [1] + (2..n).map{|i| a = (i.to_s(2) * i + a.to_s).to_i}
end
p A300558(10)

Crossrefs

Cf. A007088, A300517, A300557.

Sequence in context: A267876 A353110 A144863 * A227407 A227409 A352947

Adjacent sequences: A300555 A300556 A300557 * A300559 A300560 A300561

Keyword

nonn,base

Author

Seiichi Manyama, Mar 08 2018

Status

approved