A162473 Write n in binary n times and concatenate (see example). a(n) is the decimal equivalent.

1, 10, 63, 2340, 23405, 224694, 2097151, 2290649224, 41231686041, 733007751850, 12900936432571, 225179981368524, 3903119677054429, 67253754435399406, 1152921504606846975, 623961713349486025654800, 21214698253882524872263217, 718803893778607901554330194

Offset

1,2

Links

Alois P. Heinz, Table of n, a(n) for n = 1..369

Formula

a(n) = n * (2^(A070939(n)*n) - 1) / (2^(A070939(n)) - 1). - Maxim Skorohodov, Oct 26 2020

Example

The binary representations of the first few terms are 1, 1010, 111111, 100100100100, 101101101101101.

Maple

A070939 := proc(n) max(1, ilog2(n)+1) ; end: A162473 := proc(n) local bid, a062383; bid := A070939(n) ; a062383 := 2^bid ; n*(a062383^n-1)/(a062383-1) ; end: seq(A162473(n), n=1..30) ; # R. J. Mathar, Jul 06 2009
# second Maple program:
a:= n-> Bits[Join](map(x-> x[], [Bits[Split](n)$n])):
seq(a(n), n=1..30);  # Alois P. Heinz, Oct 26 2020

Mathematica

Table[FromDigits[Flatten[Table[IntegerDigits[n, 2], {n}]], 2], {n, 20}] (* Harvey P. Dale, Jun 15 2021 *)

Crossrefs

Cf. A007088, A070939, A162472.

Sequence in context: A075755 A046638 A101467 * A138661 A341681 A269538

Adjacent sequences: A162470 A162471 A162472 * A162474 A162475 A162476

Keyword

base,nonn

Author

Leroy Quet, Jul 04 2009

Extensions

More terms from R. J. Mathar, Jul 06 2009

Status

approved