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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

AUTHOR

N. J. A. Sloane.

EXTENSIONS

Definition rewritten by Eric M. Schmidt, Apr 18 2013

STATUS

approved

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Last modified December 9 10:23 EST 2016. Contains 278971 sequences.