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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 (list; table; graph; refs; listen; history; text; internal format)
 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 Cf. A000010, A000040. Sequence in context: A369291 A074912 A274207 * A331813 A215244 A195427 Adjacent sequences: A158499 A158500 A158501 * A158503 A158504 A158505 KEYWORD nonn,tabl,easy AUTHOR R. J. Mathar, Aug 29 2011 STATUS approved

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Last modified June 19 03:10 EDT 2024. Contains 373492 sequences. (Running on oeis4.)