login
This site is supported by donations to The OEIS Foundation.

 

Logo


Hints
(Greetings from The On-Line Encyclopedia of Integer Sequences!)
A070871 A002487(n)*A002487(n+1) (Conway's alimentary function). 10
1, 2, 2, 3, 6, 6, 3, 4, 12, 15, 10, 10, 15, 12, 4, 5, 20, 28, 21, 24, 40, 35, 14, 14, 35, 40, 24, 21, 28, 20, 5, 6, 30, 45, 36, 44, 77, 70, 30, 33, 88, 104, 65, 60, 84, 63, 18, 18, 63, 84, 60, 65, 104, 88, 33, 30, 70, 77, 44, 36, 45, 30, 6, 7, 42, 66 (list; graph; refs; listen; history; text; internal format)
OFFSET

1,2

LINKS

Indranil Ghosh, Table of n, a(n) for n = 1..16384

Robert G. Wilson v, Plot of first 4096 terms

FORMULA

Sum of reciprocals of k-th "chunk" (between two entries k) = 1 (for example for the third chunk, 1/3 + 1/6 + 1/6 + 1/3 = 1).

MATHEMATICA

a[0] = 1; a[n_] := If[ OddQ[n], a[n/2 - 1/2], a[n/2] + a[n/2 - 1]]; Table[ a[n - 1]*a[n], {n, 1, 70}]

PROG

(Python)

def a002487(n): return n if n<2 else a002487(n/2) if n%2==0 else a002487((n - 1)/2) + a002487((n + 1)/2)

def a(n): return a002487(n)*a002487(n + 1) # Indranil Ghosh, Jun 08 2017

CROSSREFS

Cf. A002487, A070872-A070874.

Sequence in context: A132886 A119272 A308483 * A096115 A289838 A290734

Adjacent sequences:  A070868 A070869 A070870 * A070872 A070873 A070874

KEYWORD

nonn

AUTHOR

N. J. A. Sloane, May 19 2002

STATUS

approved

Lookup | Welcome | Wiki | Register | Music | Plot 2 | Demos | Index | Browse | More | WebCam
Contribute new seq. or comment | Format | Style Sheet | Transforms | Superseeker | Recent
The OEIS Community | Maintained by The OEIS Foundation Inc.

License Agreements, Terms of Use, Privacy Policy. .

Last modified October 22 18:44 EDT 2019. Contains 328319 sequences. (Running on oeis4.)