A076352 Squarefree numbers k such that A076341(k) = 0.

1, 2, 15, 30, 143, 286, 2145, 3599, 4290, 5183, 7198, 10366, 11663, 23326, 32399, 36863, 51983, 53985, 57599, 64798, 73726, 77745, 97343, 103966, 107970, 115198, 121103, 155490, 174945, 176399, 186623, 194686, 242206, 349890, 352798, 359999, 373246, 435599, 485985

Offset

1,2

Links

Table of n, a(n) for n=1..39.

Example

Applying the map as defined in A076340, A076341:
A005117(19) = 30 = 5*3*2 = (4+1)*(4-1)*2 -> (4,1)*(4,-1)*(2,0) = (4*4+1,4-4)*(2,0) = (34,0), therefore A076340(30) = 34 and A076341(30) = 0, hence 30 is a term.
A005117(28) = 42 = 7*3*2 = (8-1)*(4-1)*2 -> (8,-1)*(4,-1)*(2,0) = (8*4-1,-8-4)*(2,0) = (62,-24), therefore A076340(42) = 62 and A076341(42) = -24, hence 42 is not a term.

Mathematica

f[p_, e_] := 4*(Floor[p/4] + Floor[Mod[p, 4]/2]) + (2 - Mod[p, 4])*I; f[2, e_] := 2; s[1] = 1; s[n_] := Times @@ f @@@ FactorInteger[n]; Select[Range[500000], SquareFreeQ[#] && Im[s[#]] == 0 &] (* Amiram Eldar, Feb 24 2024 *)

Crossrefs

Cf. A005117, A076340, A076341, A076348.

Sequence in context: A071999 A031289 A093917 * A154790 A042461 A196263

Adjacent sequences: A076349 A076350 A076351 * A076353 A076354 A076355

Keyword

nonn

Author

Reinhard Zumkeller, Oct 08 2002

Extensions

More terms from Amiram Eldar, Feb 24 2024

Status

approved