A300570 a(n) is the concatenation n in base 2, n-1 in base 2, ..., 1 in base 2.

1, 101, 11101, 10011101, 10110011101, 11010110011101, 11111010110011101, 100011111010110011101, 1001100011111010110011101, 10101001100011111010110011101, 101110101001100011111010110011101, 1100101110101001100011111010110011101

Offset

1,2

Links

Seiichi Manyama, Table of n, a(n) for n = 1..155

Index entries for sequences related to Most Wanted Primes video

Maple

a:= proc(n) option remember; `if`(n=1, 1,
      parse(cat(convert(n, binary), a(n-1))))
    end:
seq(a(n), n=1..12);  # Alois P. Heinz, Feb 19 2023

Mathematica

Table[FromDigits[Flatten[IntegerDigits[#, 2]&/@Range[n, 1, -1]]], {n, 20}] (* Harvey P. Dale, Sep 07 2020 *)

Prog

(Python)
from itertools import count, islice
def agen(): # generator of terms
    s = ""
    for k in count(1):
        s = bin(k)[2:] + s
        yield int(s)
print(list(islice(agen(), 15))) # Michael S. Branicky, Feb 19 2023
(Python)
from functools import reduce
def A300570(n): return int(bin(reduce(lambda i, j:(i<<j.bit_length())+j, range(n, 0, -1)))[2:]) # Chai Wah Wu, Feb 26 2023

Crossrefs

Cf. A007088, A058935, A300571.

Cf. A098780 (decimal expansion of terms).

Sequence in context: A138148 A138831 A267920 * A171825 A267937 A185893

Adjacent sequences: A300567 A300568 A300569 * A300571 A300572 A300573

Keyword

nonn,base

Author

Seiichi Manyama, Mar 08 2018

Status

approved