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A117762 a(1)=6. a(n) = prime(n)*( (prime(n)^2-1 )/2 if n>1. 1
6, 12, 60, 168, 660, 1092, 2448, 3420, 6072, 12180, 14880, 25308, 34440, 39732, 51888, 74412, 102660, 113460, 150348, 178920, 194472, 246480, 285852, 352440, 456288 (list; graph; refs; listen; history; text; internal format)
OFFSET

1,1

COMMENTS

Order of SL(2,prime(n)) groups.

REFERENCES

Blyth and Robertson, Essential Student Algebra, Volume 5: Groups,Chapman and Hall, New York, page 14

LINKS

Table of n, a(n) for n=1..25.

FORMULA

a(n) = A127918(n), n>1.

MATHEMATICA

f[n_] = If[Prime[n] - 2 == 0, 6, Prime[n]*(Prime[n]^2 - 1)/2] a = Table[f[n], {n, 1, 25}]

CROSSREFS

Sequence in context: A033931 A228847 A093901 * A178957 A104362 A123900

Adjacent sequences:  A117759 A117760 A117761 * A117763 A117764 A117765

KEYWORD

nonn,easy

AUTHOR

Roger L. Bagula, Apr 14 2006

STATUS

approved

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Last modified August 28 13:11 EDT 2015. Contains 261122 sequences.