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A090977
Least k such that k*prime(k) > 10^n.
2
1, 3, 7, 17, 48, 134, 382, 1115, 3287, 9786, 29296, 88181, 266694, 809599, 2465574, 7528976, 23045352, 70684657, 217196605, 668461874, 2060257099, 6358076827, 19644205359, 60757729194, 188099056251, 582846849914, 1807483210259, 5609430824151, 17420628067997
OFFSET
0,2
COMMENTS
Does lim_{n->oo} a(n+1)/a(n) exist? If so, is the limit Pi? - Ryan Propper, Sep 15 2005
LINKS
Robert G. Wilson v, Table of n, a(n) for n = 0..36 (terms 1..36 from Chai Wah Wu).
EXAMPLE
a(3) = 17 as 17*prime(17) = 17*59 = 1003 > 10^3.
MAPLE
for n from 0 to 11 do b:=proc(k) if k*ithprime(k)>10^n then k else fi end: a[n]:=[seq(b(k), k=1..100000)][1]: od: seq(a[n], n=0..11); # Emeric Deutsch, Aug 04 2005
MATHEMATICA
n = 0; For[k = 1, k > 0, k++, If[k*Prime[k] > 10^n, Print[k]; n++ ]] (* Ryan Propper, Sep 15 2005 and modified by Robert G. Wilson v, Feb 25 2019 to reflect the offset of 0 *)
CROSSREFS
Sequence in context: A071985 A181419 A371866 * A324789 A014144 A247183
KEYWORD
nonn,base
AUTHOR
Amarnath Murthy, Jan 04 2004
EXTENSIONS
More terms from Emeric Deutsch, Aug 04 2005
More terms from Ryan Propper, Sep 15 2005
a(20)-a(28) from Chai Wah Wu, Apr 29 2018
a(0)=1 prepended by Robert G. Wilson v, Feb 25 2019
STATUS
approved