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A081633 Class 5+ primes (for definition see A005105). 21
1021, 1321, 1381, 1459, 1877, 2467, 2503, 2657, 2707, 3253, 3313, 3547, 3701, 3733, 3907, 4561, 4817, 4937, 5441, 5443, 5527, 5693, 5839, 5861, 6037, 6131, 6211, 6217, 6277, 6361, 6373, 6569, 6653, 7057, 7243, 7591, 7753, 7817, 7883, 8101, 8123, 8221 (list; graph; refs; listen; history; text; internal format)
OFFSET
1,1
REFERENCES
R. K. Guy, Unsolved Problems in Number Theory, A18.
LINKS
MAPLE
For Maple program see Mathar link in A005105.
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]]; ClassPlusNbr[n_] := Length[ NestWhileList[f, n, UnsameQ, All]] - 3; Prime[ Select[ Range[1040], ClassPlusNbr[ Prime[ # ]] == 5 &]]
CROSSREFS
Sequence in context: A179032 A179033 A082059 * A020388 A362361 A306596
KEYWORD
nonn
AUTHOR
Robert G. Wilson v, Mar 20 2003
STATUS
approved

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Last modified March 29 11:45 EDT 2024. Contains 371278 sequences. (Running on oeis4.)