A090096 Least n-pseudoprime which is a power of a prime number; smallest prime-power pseudoprime to base n.

4, 1194649, 121, 1194649, 4, 4377277921, 25, 9, 4, 9, 5041, 7252249, 4, 841, 848615161, 1194649, 4, 25, 9, 78961, 4, 169, 169, 25, 4, 9, 121, 9, 4, 49, 49, 25, 4, 2129445719544546771481, 9, 4377277921, 4, 289, 64625521, 121, 4, 529, 25, 9, 4, 9

Offset: 1

Author

Labos Elemer, Dec 01 2003

Keywords

• nonn
• more

Examples

			n=2: -1+2^(1092*1094) = K*1093*1093 = K*1194649;
n=4k+1: a(4k+1)=4; for a(k)=9 see A090097; a(k)=25 see A090098.
Some large values after a(46): a(52)=219521; a(56)=418609; a(58)=17161; a(59)=7711729; a(83)=23726641; a(84)=26569; a(86)=4656561121; a(87)=3996001; a(92)=528529; a(95)=4566769; a(96)=11881.
Hard bases below 100 are 47, 66, 72, 88, 90.
		

Links

• Index entries for sequences related to pseudoprimes

Crossrefs

Cf. A007535, A090086, A247072, A039951.

Programs

Mathematica

t=list-of-true-p-powers-generated-independently lf[x_] := Length[FactorInteger[x]] base=6;Do[s=Mod[ -1+base^(Part[t, n]-1), Part[t, n]]; If[Equal[s, 0], Print[Part[t, n]]], {n, 1, Length[t]}]

Formula

a(n) = A039951(n)^2.

Extensions

More terms from Michel Marcus, Aug 30 2019