A089133 - OEIS

A089133

a(n) = If [ Mod[A001591[n], 1]=1 then A001591[n] else A001591[n]+1 If PrimeQ[a[n]]==True then a[n]

3, 5, 17, 31, 61, 3040049, 5976577, 585029621921, 7536799430533853, 15114377875501666690812160076212633379799041, 4625477479238789293261951042221574153801685983374041180119163207681

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OFFSET

1,1

LINKS

Table of n, a(n) for n=1..11.

MATHEMATICA

digits = 50

NSolve[x^5-x^4-x^3-x^2-x-1==0, x]

k=1.96594823664548545

q=k^2-k-1/k-1/k^2-1/k^3

m0={{0, 1, 0, 0, 0}, {0, 0, 1, 0, 0}, {0, 0, 0, 1, 0}, {0, 0, 0, 0, 1}, {1, 1, 1, 1, q}}

m[n_]=MatrixPower[m0, n];

a=Table[If[Mod[Floor[Re[m[n][[5, 5]]]], 2]==1, Floor[Re[m[n][[5, 5]]]], Floor[Re[m[n][[5, 5]]]]+1], {n, 1, digits}];

b=Table[If[PrimeQ[a[[n]]]==True, a[[n]], 0], {n, 1, digits}];

c=Delete[Union[b], 1]

CROSSREFS

Cf. A001591.

Sequence in context: A038898 A333353 A297175 * A103149 A372012 A007802

Adjacent sequences: A089130 A089131 A089132 * A089134 A089135 A089136

KEYWORD

nonn,uned,less

AUTHOR

Roger L. Bagula, Dec 05 2003

STATUS

approved