|
| |
|
|
A178740
|
|
Product of the 5th power of a prime (A050997) and a different prime (p^5*q).
|
|
9
|
|
|
|
96, 160, 224, 352, 416, 486, 544, 608, 736, 928, 992, 1184, 1215, 1312, 1376, 1504, 1696, 1701, 1888, 1952, 2144, 2272, 2336, 2528, 2656, 2673, 2848, 3104, 3159, 3232, 3296, 3424, 3488, 3616, 4064, 4131, 4192, 4384, 4448, 4617, 4768, 4832, 5024, 5216
(list;
graph;
refs;
listen;
history;
text;
internal format)
|
|
|
|
OFFSET
|
1,1
|
|
|
COMMENTS
|
Subsequence of A030630, integers whose number of divisors is 12. - Michel Marcus, Nov 11 2015
|
|
|
LINKS
|
T. D. Noe, Table of n, a(n) for n = 1..1000
Index to sequences related to prime signature
|
|
|
FORMULA
|
Solutions of the equation tau(n^5)=13*tau(n) where tau(n) is the number of divisors of n. - Paolo P. Lava, Mar 15 2013
|
|
|
MAPLE
|
with(numtheory);
A178740:=proc(q) local n;
for n from 1 to q do if tau(n^5)=13*tau(n) then print(n); fi; od; end:
A178740(10^10); # Paolo P. Lava, Mar 15 2013
|
|
|
MATHEMATICA
|
f[n_]:=Sort[Last/@FactorInteger[n]]=={1, 5}; Select[Range[6000], f] (* Vladimir Joseph Stephan Orlovsky, May 03 2011 *)
With[{nn=50}, Take[Union[Flatten[{#[[1]]^5 #[[2]], #[[1]]#[[2]]^5}&/@Subsets[ Prime[ Range[nn]], {2}]]], nn]] (* Harvey P. Dale, Mar 18 2013 *)
|
|
|
PROG
|
(PARI) list(lim)=my(v=List(), t); forprime(p=2, (lim\2)^(1/5), t=p^5; forprime(q=2, lim\t, if(p==q, next); listput(v, t*q))); vecsort(Vec(v)) \\ Altug Alkan, Nov 11 2015
(PARI) isok(n)=my(f=factor(n)[, 2]); f==[5, 1]~||f==[1, 5]~
for(n=1, 1e4, if(isok(n), print1(n, ", "))) \\ Altug Alkan, Nov 11 2015
|
|
|
CROSSREFS
|
Cf. A178739, A050997 and A143610.
Sequence in context: A116119 A039600 A143847 * A090762 A206337 A161482
Adjacent sequences: A178737 A178738 A178739 * A178741 A178742 A178743
|
|
|
KEYWORD
|
easy,nonn
|
|
|
AUTHOR
|
Will Nicholes, Jun 08 2010
|
|
|
STATUS
|
approved
|
| |
|
|
