Logo

Greetings from The On-Line Encyclopedia of Integer Sequences!

Hints

Search: id:A081427
Displaying 1-1 of 1 results found. page 1
     Format: long | short | internal | text      Sort: relevance | references | number      Highlight: on | off
A081427 Class 8- primes. +0
13
2879, 20147, 25903, 34537, 46049, 58733, 63317, 65267, 69029, 69073, 74759, 80537, 86291, 86341, 103549, 106487, 108413, 112877, 120877, 131687, 135859, 138053, 140939, 141023, 147647, 155413, 157427, 165527, 172681, 187163, 189949, 207079 (list; graph; listen)
OFFSET

1,1

REFERENCES

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

LINKS

R. J. Mathar, Table of n, a(n) for n = 1..20000

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[20000], ClassMinusNbr[ Prime[ # ]] == 8 &]]

CROSSREFS

Cf. A005113, A056637, A005109, A005110, A005111, A005112, A081424, A081425, A081426, A081428, A081429, A081430.

Sequence in context: A020429 A067703 A125000 this_sequence A101999 A066174 A134856

Adjacent sequences: A081424 A081425 A081426 this_sequence A081428 A081429 A081430

KEYWORD

nonn

AUTHOR

Robert G. Wilson v (rgwv(AT)rgwv.com), Mar 20 2003

page 1

Search completed in 0.002 seconds

Lookup | Welcome | Find friends | Music | Plot 2 | Demos | Index | Browse | More | WebCam
Contribute new seq. or comment | Format | Transforms | Puzzles | Hot | Classics
More pages | Superseeker | Maintained by N. J. A. Sloane (njas@research.att.com)

Last modified November 30 13:13 EST 2009. Contains 167758 sequences.


AT&T Labs Research