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A158502
Array T(n,k) read by antidiagonals: number of primitive polynomials of degree k over GF(prime(n)).
1
1, 1, 1, 2, 2, 2, 2, 4, 4, 2, 4, 8, 20, 8, 6, 4, 16, 36, 48, 22, 6, 8, 24, 144, 160, 280, 48, 18, 6, 48, 240, 960, 1120, 720, 156, 16, 10, 48, 816, 1536, 12880, 6048, 5580, 320, 48, 12, 80, 756, 5376, 24752, 62208, 37856, 14976, 1008, 60, 8, 96, 1560, 8640, 141984, 224640, 1087632, 192000, 99360
OFFSET
1,4
LINKS
Vincenzo Librandi, Rows n = 1..50, flattened
FORMULA
T(n,k) = A000010(p^k-1)/k with p=A000040(n).
EXAMPLE
The array starts in row n=1 with columns k>=1 as
1, 1, 2, 2, 6, 6, 18, 16, 48, 60, A011260
1, 2, 4, 8, 22, 48, 156, 320, 1008, 2640, A027385
2, 4, 20, 48, 280, 720, 5580, 14976, 99360, 291200, A027741
2, 8, 36, 160, 1120, 6048, 37856, 192000, 1376352, 8512000, A027743
4,16, 144, 960, 12880, 62208,1087632,7027200,85098816,691398400,
4,24, 240, 1536, 24752, 224640,2988024,21934080
MAPLE
A := proc(n, k) local p ; p := ithprime(n) ; if k = 0 then 1; else numtheory[phi](p^k-1)/k ; end if; end proc:
MATHEMATICA
t[n_, k_] := If[k == 0, 1, p = Prime[n]; EulerPhi[p^k - 1]/k]; Flatten[ Table[t[n - k + 1, k], {n, 1, 11}, {k, 1, n}]] (* Jean-François Alcover, Jun 04 2012, after Maple *)
CROSSREFS
Sequence in context: A369291 A074912 A274207 * A331813 A215244 A195427
KEYWORD
nonn,tabl,easy
AUTHOR
R. J. Mathar, Aug 29 2011
STATUS
approved