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A178739 Product of the 4th power of a prime (A030514) and a different prime. 32
48, 80, 112, 162, 176, 208, 272, 304, 368, 405, 464, 496, 567, 592, 656, 688, 752, 848, 891, 944, 976, 1053, 1072, 1136, 1168, 1250, 1264, 1328, 1377, 1424, 1539, 1552, 1616, 1648, 1712, 1744, 1808, 1863, 1875, 2032, 2096, 2192, 2224, 2349, 2384, 2416, 2511 (list; graph; refs; listen; history; text; internal format)
OFFSET

1,1

COMMENTS

Most of the terms in A030628 also appear here but 1 and 512 are excluded.

LINKS

T. D. Noe, Table of n, a(n) for n = 1..1000

FORMULA

Solutions of the equation tau(n^9)=37*tau(n). - Paolo P. Lava, Mar 15 2013

a(n) ~ kn log n with k = 1/P(4) = 1/A085964 = 12.98817.... - Charles R Greathouse IV, Feb 23 2017

MAPLE

with(numtheory);

A178739:=proc(q) local n;

for n from 1 to q do if tau(n^9)=37*tau(n) then print(n); fi; od; end:

A178739(10^10);  # Paolo P. Lava, Mar 15 2013

MATHEMATICA

f[n_]:=Sort[Last/@FactorInteger[n]]=={1, 4}; Select[Range[10000], f] (* Vladimir Joseph Stephan Orlovsky, May 03 2011 *)

max = 500000; A178739 = DeleteCases[Union[Table[Prime[p] Prime[q]^4 Boole[p != q], {p, PrimePi[max/16]}, {q, PrimePi[max/2]}]], 0]; Take[A178739, 50] (* Alonso del Arte, Aug 05 2012 *)

PROG

(PARI) list(lim)=my(v=List(), t); forprime(p=2, (lim\2)^(1/4), t=p^4; forprime(q=2, lim\t, if(p==q, next); listput(v, t*q))); vecsort(Vec(v)) \\ Charles R Greathouse IV, Jul 20 2011

CROSSREFS

Cf. A065036, A030514, A030628, A085986, A085987.

Sequence in context: A110229 A108608 A030628 * A261548 A065911 A260841

Adjacent sequences:  A178736 A178737 A178738 * A178740 A178741 A178742

KEYWORD

easy,nonn

AUTHOR

Will Nicholes, Jun 08 2010

STATUS

approved

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Last modified March 24 03:50 EDT 2017. Contains 283984 sequences.