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A081429
Class 10- primes.
12
138197, 207227, 621679, 621883, 633383, 760079, 829177, 863711, 898253, 978863, 1035499, 1036471, 1209191, 1451059, 1566179, 1658309, 1658353, 1761407, 1794229, 1796503, 1827479, 1900147, 2015303, 2029439, 2070997, 2072893
OFFSET
1,1
REFERENCES
R. K. Guy, Unsolved Problems in Number Theory, A18.
LINKS
MATHEMATICA
PrimeFactors[n_Integer] := Flatten[Table[ #[[1]], {1}] & /@ FactorInteger[n]]; f[n_Integer] := Block[{m = n}, If[m == 0, m = 1, While[ IntegerQ[m/2], m /= 2]; While[ IntegerQ[m/3], m /= 3]]; Apply[Times, PrimeFactors[m] - 1]]; ClassMinusNbr[n_] := Length[NestWhileList[f, n, UnsameQ, All]] - 3; Prime[ Select[ Range[200000], ClassMinusNbr[ Prime[ # ]] == 10 &]]
KEYWORD
nonn
AUTHOR
Robert G. Wilson v, Mar 20 2003
STATUS
approved