A081636 Class 8+ primes.
49681, 109441, 120103, 151561, 198733, 210193, 246241, 255043, 266401, 280243, 295873, 326659, 326701, 347773, 355171, 360421, 368881, 397633, 397673, 423001, 441877, 447137, 471241, 480541, 489989, 499397, 508037, 511507, 532757, 539401
Offset: 1
Keywords
References
- R. K. Guy, Unsolved Problems in Number Theory, A18.
Links
- T. D. Noe, Table of n, a(n) for n=1..10000
Crossrefs
Programs
-
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[44535], ClassPlusNbr[ Prime[ # ]] == 8 &]]