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

1,1

References

R. K. Guy, Unsolved Problems in Number Theory, A18.

Links

T. D. Noe, Table of n, a(n) for n=1..10000

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 &]]

Crossrefs

Cf. A005113, A005105, A005106, A005107, A005108, A081633, A081634, A081635, A081637, A081638, A081639.

Sequence in context: A187856 A258320 A258131 * A151636 A023944 A159233

Adjacent sequences: A081633 A081634 A081635 * A081637 A081638 A081639

Keyword

nonn

Author

Robert G. Wilson v, Mar 20 2003

Status

approved