A073019 Numbers n such that the absolute value of the real part of (1+2*I)^n is prime.
2, 3, 4, 5, 7, 11, 13, 17, 19, 89, 163, 167, 233, 251, 349, 401, 757, 1423, 3049, 3643, 11987, 19801, 26393, 32303, 35363, 35863, 36607, 36683
Offset: 1
Keywords
Crossrefs
Cf. A006495.
Programs
-
Maple
A006495 := proc(n) add((-4)^l*binomial(n,2*l),l=0..floor(n/2)) ; end proc: isA073019 := proc(n) isprime(abs(A006495(n))) ; end proc: for n from 1 do if isA073019(n) then print(n) ; end if; end do: # R. J. Mathar, Sep 06 2011
-
Mathematica
x=1; For[n=1, n<=14000, n++, {x=(1+2*I)*x, If[PrimeQ[Re[x]], Print[n]]}] -
PARI
is(n)=ispseudoprime(abs(real((1+2*I)^n))) \\ Charles R Greathouse IV, Nov 21 2014
Extensions
Edited by John W. Layman, Aug 13 2002
a(21) from Robert G. Wilson v, Aug 22 2002
a(22)-a(28) from Charles R Greathouse IV, Nov 25 2014
Comments