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A098780 First n numbers in binary representation concatenated in reverse order. 4
1, 5, 29, 157, 1437, 13725, 128413, 1176989, 20051357, 355595677, 6261175709, 109340390813, 1896046785949, 32682372363677, 560447953696157, 9567647208437149, 315812421869630877, 10692105963331253661 (list; graph; refs; listen; history; text; internal format)
OFFSET

1,2

LINKS

Indranil Ghosh, Table of n, a(n) for n = 1..412

FORMULA

a(n) = n*A000079(A070939(a(n-1))) + a(n-1); a(1) = 1.

a(n) = n*2^(1 + floor(log_2(a(n-1)))) + a(n-1); a(1) = 1.

EXAMPLE

a(4) = (4 3 2 1) -> (100 11 10 1) -> 10011101 -> 157.

PROG

(Python)

def A098780(n):

....s=""

....for i in range(n, 0, -1):

........s+=bin(i)[2:]

....return int(s, 2) # Indranil Ghosh, Jan 28 2017

CROSSREFS

Cf. A007088, A047778.

Sequence in context: A060926 A239715 A260752 * A222700 A272940 A146178

Adjacent sequences:  A098777 A098778 A098779 * A098781 A098782 A098783

KEYWORD

nonn,base

AUTHOR

Reinhard Zumkeller, Oct 04 2004

EXTENSIONS

Typo in data corrected by D. S. McNeil, Aug 20 2010

STATUS

approved

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Last modified August 17 20:59 EDT 2017. Contains 290655 sequences.