A069114 Squarefree part of prime(n)-1 : the smallest number such that a(n)*(prime(n)-1) is a square.

1, 2, 1, 6, 10, 3, 1, 2, 22, 7, 30, 1, 10, 42, 46, 13, 58, 15, 66, 70, 2, 78, 82, 22, 6, 1, 102, 106, 3, 7, 14, 130, 34, 138, 37, 6, 39, 2, 166, 43, 178, 5, 190, 3, 1, 22, 210, 222, 226, 57, 58, 238, 15, 10, 1, 262, 67, 30, 69, 70, 282, 73, 34, 310, 78, 79, 330, 21, 346, 87

Offset

1,2

Links

Amiram Eldar, Table of n, a(n) for n = 1..10000

Formula

a(n) = A007913(A006093(n)). - Amiram Eldar, Sep 03 2020

Mathematica

core[n_] := Times @@ (First[#]^Mod[Last[#], 2]& /@ FactorInteger[n]); core /@ (Select[Range[350], PrimeQ] - 1) (* Amiram Eldar, Sep 03 2020 *)

Prog

(PARI) for(n=1, 100, print1(core(prime(n)-1), ", "))

Crossrefs

Cf. A006093, A007913, A069115.

Sequence in context: A177863 A193601 A157402 * A173773 A305512 A121927

Adjacent sequences: A069111 A069112 A069113 * A069115 A069116 A069117

Keyword

easy,nonn,changed

Author

Benoit Cloitre, Apr 06 2002

Status

approved