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

 

Logo


Hints
(Greetings from The On-Line Encyclopedia of Integer Sequences!)
A061462 The exact power of 2 that divides the n-th Bell number (A000110). Has period 12. 1
1, 1, 2, 1, 1, 4, 1, 1, 4, 1, 1, 2, 1, 1, 2, 1, 1, 4, 1, 1, 4, 1, 1, 2, 1, 1, 2, 1, 1, 4, 1, 1, 4, 1, 1, 2, 1, 1, 2, 1, 1, 4, 1, 1, 4, 1, 1, 2, 1, 1, 2, 1, 1, 4, 1, 1, 4, 1, 1, 2, 1, 1, 2, 1, 1, 4, 1, 1, 4, 1, 1, 2, 1, 1, 2, 1, 1, 4, 1, 1, 4, 1, 1, 2, 1, 1, 2, 1, 1, 4, 1, 1, 4, 1, 1, 2, 1, 1, 2, 1, 1, 4, 1, 1, 4, 1, 1, 2 (list; graph; refs; listen; history; text; internal format)
OFFSET

0,3

COMMENTS

{ Bell(n) mod 8 } is periodic with period 24, the period being (1 1 2 5 7 4 3 5 4 3 7 2 5 5 2 1 3 4 7 1 4 7 3 2). Hence the highest power of 2 dividing a Bell number is 4. - David W. Wilson, Jun 29 2001

REFERENCES

W. F. Lunnon, P. A. B. Pleasants and N. M. Stephens, Arithmetic properties of Bell numbers to a composite modulus I, Acta Arithmetica 35 (1979) 1-16.

LINKS

Table of n, a(n) for n=0..107.

Index entries for linear recurrences with constant coefficients, signature (0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 1).

FORMULA

a(n) = (1/396)*{43*(n mod 12)-23*[(n+1) mod 12]+10*[(n+2) mod 12]+109*[(n+3) mod 12]-89*[(n+4) mod 12]+10*[(n+5) mod 12]+109*[(n+6) mod 12]-89*[(n+7) mod 12]+10*[(n+8) mod 12]+43*[(n+9) mod 12]-23*[(n+10) mod 12]+10*[(n+11) mod 12]}, with n>=0. - Paolo P. Lava, Oct 22 2008

MATHEMATICA

PadRight[{}, 120, {1, 1, 2, 1, 1, 4, 1, 1, 4, 1, 1, 2}] (* Harvey P. Dale, Sep 24 2017 *)

PROG

(PARI) a(n)=[1, 1, 2, 1, 1, 4, 1, 1, 4, 1, 1, 2][n%12+1] \\ Charles R Greathouse IV, Jul 13 2016

CROSSREFS

Cf. A000110.

Sequence in context: A099238 A141450 A209690 * A294334 A122578 A208648

Adjacent sequences:  A061459 A061460 A061461 * A061463 A061464 A061465

KEYWORD

nonn,easy

AUTHOR

Ahmed Fares (ahmedfares(AT)my-deja.com), Jun 10 2001

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 | More pages
The OEIS Community | Maintained by The OEIS Foundation Inc.

License Agreements, Terms of Use, Privacy Policy. .

Last modified October 22 21:09 EDT 2018. Contains 316505 sequences. (Running on oeis4.)