|
|
A186946
|
|
The smallest integer x > 0 such that the number of prime powers p^k (k>=1) in (x/2,x] equals n.
|
|
1
|
|
|
2, 3, 5, 9, 13, 25, 29, 31, 43, 49, 71, 73, 81, 103, 109, 113, 127, 131, 139, 157, 173, 181, 191, 193, 199, 239, 241, 269, 271, 283, 289, 293, 313, 349, 353, 361, 373, 379, 409, 419, 421, 433, 439, 443, 463, 499, 509, 523, 571, 577, 599, 601, 607, 613, 619
(list;
graph;
refs;
listen;
history;
text;
internal format)
|
|
|
OFFSET
|
1,1
|
|
COMMENTS
|
An analog of Labos primes (A080359) on prime powers>1 (A000961).
|
|
LINKS
|
Peter J. C. Moses, Table of n, a(n) for n = 1..10000
|
|
FORMULA
|
a(n) <= A186945(n).
|
|
MATHEMATICA
|
a000961Q[n_]:=(Length[FactorInteger[n]]==1) && IntegerQ[n]; nn=99; t=Table[0, {nn+1}]; s=0; Do[If[a000961Q[k], s++]; If[a000961Q[k/2], s--]; If[s<=nn && t[[s+1]]==0, t[[s+1]]=k], {k, 2, Prime[3*nn]}]; Prepend[Rest[t], 2] (* after T. D. Noe's code at A080359 *)(* Peter J. C. Moses, Sep 11 2013 *)
|
|
CROSSREFS
|
Cf. A080459, A186945, A228520, A228592.
Sequence in context: A228129 A175125 A171925 * A057225 A309289 A220315
Adjacent sequences: A186943 A186944 A186945 * A186947 A186948 A186949
|
|
KEYWORD
|
nonn
|
|
AUTHOR
|
Vladimir Shevelev, Aug 30 2013
|
|
EXTENSIONS
|
More terms from Peter J. C. Moses, Aug 30 2013
|
|
STATUS
|
approved
|
|
|
|