|
|
A179666
|
|
Products of the 4th power of a prime and a distinct prime of power 3 (p^4*q^3).
|
|
13
|
|
|
432, 648, 2000, 5000, 5488, 10125, 16875, 19208, 21296, 27783, 35152, 64827, 78608, 107811, 109744, 117128, 177957, 194672, 214375, 228488, 300125, 390224, 395307, 397953, 476656, 555579, 668168, 771147, 810448, 831875
(list;
graph;
refs;
listen;
history;
text;
internal format)
|
|
|
OFFSET
|
1,1
|
|
LINKS
|
|
|
FORMULA
|
|
|
MATHEMATICA
|
f[n_]:=Sort[Last/@FactorInteger[n]]=={3, 4}; Select[Range[10^6], f]
With[{nn=40}, Select[Flatten[{#[[1]]^4 #[[2]]^3, #[[1]]^3 #[[2]]^4}&/@ Subsets[ Prime[Range[nn]], {2}]]//Union, #<=16nn^3&]] (* Harvey P. Dale, Nov 15 2020 *)
|
|
PROG
|
(PARI) list(lim)=my(v=List(), t); forprime(p=2, (lim\8)^(1/4), t=p^4; forprime(q=2, (lim\t)^(1/3), if(p==q, next); listput(v, t*q^3))); vecsort(Vec(v)) \\ Charles R Greathouse IV, Jul 20 2011
|
|
CROSSREFS
|
|
|
KEYWORD
|
nonn
|
|
AUTHOR
|
|
|
STATUS
|
approved
|
|
|
|