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

 

Logo


Hints
(Greetings from The On-Line Encyclopedia of Integer Sequences!)
A032444 a(1) = 1, a(2) = 16, a(n) = LCM(48, 2n^2) for n>2. 0
1, 16, 144, 96, 1200, 144, 2352, 384, 1296, 1200, 5808, 288, 8112, 2352, 3600, 1536, 13872, 1296, 17328, 2400, 7056, 5808, 25392, 1152, 30000, 8112, 11664, 4704, 40368, 3600, 46128, 6144, 17424, 13872, 58800, 2592, 65712, 17328, 24336, 9600 (list; graph; refs; listen; history; text; internal format)
OFFSET

1,2

COMMENTS

In the M. Reid reference the following is proved: Let S(n) be the set of all groups whose order is a product of primes congruent to 1 mod n. Then, a(n) = gcd{|G| - |cc(G)| : G in S(n)}, where |cc(G)| is the number of conjugacy classes of G. - Eric M. Schmidt, Apr 18 2013

REFERENCES

M. Reid, The number of conjugacy classes, Amer. Math. Monthly, 105 (1998), 359-361.

LINKS

Table of n, a(n) for n=1..40.

Index to divisibility sequences

Index entries for linear recurrences with constant coefficients, signature (0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 3, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, -3, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 1).

FORMULA

a(n) = 3a(n-12) - 3a(n-24) + a(n-36) for n > 38. - Charles R Greathouse IV, Apr 18 2013

PROG

(MAGMA) [1, 16] cat [ LCM(48, 2*n^2) : n in [3..10] ]; - from Sergei Haller (sergei(AT)sergei-haller.de), Dec 21 2006

(PARI) a(n)=if(n>3, lcm(48, 2*n^2), 15*n-14) \\ Charles R Greathouse IV, Apr 18 2013

CROSSREFS

Sequence in context: A232311 A048533 A213349 * A017114 A092820 A060300

Adjacent sequences:  A032441 A032442 A032443 * A032445 A032446 A032447

KEYWORD

nonn,easy,changed

AUTHOR

N. J. A. Sloane.

EXTENSIONS

Definition rewritten by Eric M. Schmidt, Apr 18 2013

STATUS

approved

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

Content is available under The OEIS End-User License Agreement .

Last modified July 28 04:31 EDT 2015. Contains 260054 sequences.