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A090096 Least n-pseudoprime which is a power of a prime number; smallest prime-power pseudoprime to base n. 3
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 (list; graph; refs; listen; history; text; internal format)
OFFSET

1,1

LINKS

Table of n, a(n) for n=1..46.

Index entries for sequences related to pseudoprimes

FORMULA

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

EXAMPLE

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.

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]}]

CROSSREFS

Cf. A007535, A090086, A247072, A039951.

Sequence in context: A079286 A275685 A124119 * A218484 A046362 A144122

Adjacent sequences:  A090093 A090094 A090095 * A090097 A090098 A090099

KEYWORD

nonn,more

AUTHOR

Labos Elemer, Dec 01 2003

EXTENSIONS

More terms from Michel Marcus, Aug 30 2019

STATUS

approved

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Last modified April 15 20:40 EDT 2021. Contains 342977 sequences. (Running on oeis4.)