A328497 Terms of A082180 that are not squares or cubes of primes.

418, 27173, 2001341, 16024189487

Offset: 1

Author

Felix Fröhlich, Oct 17 2019

Keywords

• nonn
• hard
• more

Comments

Complement of A168363 in A082180.

Are there any other terms like 418 that are not in A228562?

No other terms below 2*10^10. - Max Alekseyev, Dec 15 2023

Crossrefs

The odd terms form A228562.

Cf. A082180, A168363.

Programs

Mathematica

Select[Range[30000], CompositeQ[#] && Not[IntegerQ[Sqrt[#]]] && Not[IntegerQ[#^(1/3)]] && Mod[Binomial[2*#, #], #] == 2 &] (* Vaclav Kotesovec, Oct 17 2019 *)

PARI

forcomposite(c=1, , if(!setintersect(Set(isprimepower(c)), [2, 3]), if(Mod(binomial(2*c, c), c)==2, print1(c, ", "))))

Extensions

a(4) from Max Alekseyev, Dec 15 2023