|
| |
|
|
A079780
|
|
a(n) = largest prime <= n*prime(n).
|
|
1
| |
|
|
2, 5, 13, 23, 53, 73, 113, 151, 199, 283, 337, 443, 523, 601, 701, 839, 997, 1097, 1259, 1409, 1531, 1733, 1907, 2131, 2423, 2621, 2777, 2971, 3137, 3389, 3931, 4177, 4519, 4723, 5209, 5431, 5807, 6173, 6491, 6917, 7333, 7591, 8209, 8467, 8863, 9151, 9907
(list; graph; refs; listen; history; internal format)
|
|
|
|
OFFSET
| 1,1
|
|
|
MAPLE
| With exception of first term: seq(prevprime(n*ithprime(n)), n=2..40);
|
|
|
MATHEMATICA
| PrevPrim[n_] := Block[{k = n - 1}, While[ !PrimeQ[k], k-- ]; k]; Table[ Abs[ PrevPrim[ n*Prime[n]]], {n, 1, 50}]
|
|
|
PROG
| (PARI) for(n=1, 47, print1(precprime(n*prime(n)), ", "))
|
|
|
CROSSREFS
| Cf. A079779.
a(n) is the largest prime < A079779(n).
Sequence in context: A049779 A106009 A194552 * A178621 A048871 A072921
Adjacent sequences: A079777 A079778 A079779 * A079781 A079782 A079783
|
|
|
KEYWORD
| nonn
|
|
|
AUTHOR
| Amarnath Murthy (amarnath_murthy(AT)yahoo.com), Feb 03 2003
|
|
|
EXTENSIONS
| Edited and extended by Robert G. Wilson v (rgwv(AT)rgwv.com), Klaus Brockhaus (klaus-brockhaus(AT)t-online.de) and Mark Hudson (mrmarkhudson(AT)hotmail.com), Feb 04 2003
|
| |
|
|
