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A078325 Squarefree numbers of the form m*rad(m)+1, where rad = A007947 (squarefree kernel). 7
2, 5, 10, 17, 26, 33, 37, 65, 73, 82, 101, 109, 122, 129, 145, 170, 197, 201, 217, 226, 257, 290, 362, 393, 401, 433, 442, 485, 501, 530, 577, 626, 649, 677, 730, 785, 842, 865, 901, 962, 969, 973, 1001, 1090, 1126, 1153, 1157, 1226, 1297, 1353, 1370, 1373 (list; graph; refs; listen; history; text; internal format)
OFFSET
1,1
LINKS
MATHEMATICA
powQ[n_] := n == 1 || AllTrue[FactorInteger[n][[;; , 2]], # > 1 &]; Select[Range[1400], SquareFreeQ[#] && powQ[# - 1] &] (* Amiram Eldar, Jul 31 2022 *)
PROG
(Haskell)
a078325 n = a078325_list !! (n-1)
a078325_list = filter ((== 1) . a008966) a224866_list
-- Reinhard Zumkeller, Jul 23 2013
(PARI) is(n) = n>1 && issquarefree(n) && ispowerful(n-1); \\ Amiram Eldar, Jul 31 2022
CROSSREFS
Intersection of A005117 and A224866.
Sequence in context: A078393 A340045 A100292 * A059591 A082607 A303372
KEYWORD
nonn
AUTHOR
Reinhard Zumkeller, Nov 23 2002
STATUS
approved

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Last modified March 19 03:33 EDT 2024. Contains 370952 sequences. (Running on oeis4.)