Logo

Greetings from The On-Line Encyclopedia of Integer Sequences!

Hints

Search: id:A060975
Displaying 1-1 of 1 results found. page 1
     Format: long | short | internal | text      Sort: relevance | references | number      Highlight: on | off
A060975 Irregular primes with irregularity index three. +0
6
491, 617, 647, 1151, 1217, 1811, 1847, 2939, 3833, 4003, 4657, 4951, 6763, 7687, 8831, 9011, 10463, 10589, 12073, 13217, 14533, 14737, 14957, 15287, 15787, 15823, 16007, 17681, 17863, 18713, 18869, 20533, 20939, 24019, 24659, 25153, 26561 (list; graph; listen)
OFFSET

1,1

REFERENCES

J. Buhler, R. Crandall, R. Ernvall, T. Metsankyla and M. A. Shokrollahi, Irregular Primes and Cyclotomic Invariants to 12 Million, J. Symbolic Computation 31, 2001, 89-96.

LINKS

T. D. Noe, Table of n, a(n) for n=1..9824 (from Buhler et al)

Bernoulli numbers, irregularity index of primes

MATHEMATICA

Do[p = Prime[n]; k = 1; c = 0; While[ 2*k < p - 3, If[ Mod[ Numerator[ BernoulliB[2*k]], p] == 0, c++ ]; k++ ]; If[ c == 3, Print[p]], {n, 3, 1000} ]

Do[p = Prime@n; k = 1; c = 0; While[ 2*k < p - 3, If[ Mod[ Numerator[ BernoulliB[2*k]], p] == 0, c++ ]; k++ ]; If[ c == 3, Print@p], {n, 3, 13887} ]

CROSSREFS

Cf. A000928, A000367, A060974, A060975, A073276 and A073277.

Sequence in context: A056936 A056052 A051115 this_sequence A082079 A007242 A116207

Adjacent sequences: A060972 A060973 A060974 this_sequence A060976 A060977 A060978

KEYWORD

nonn

AUTHOR

Robert G. Wilson v (rgwv(AT)rgwv.com), Jul 22 2002, extended Sep 20 2006

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 September 6 00:03 EDT 2008. Contains 143485 sequences.


AT&T Labs Research