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A064029 Numbers k such that sopfr(k) = ud(k), where sopfr = A001414 and ud = A034444. 1
2, 5460, 9240, 253890, 358050, 387090, 395850, 429660, 440895, 458850, 468930, 475020, 529074, 550620, 574770, 629850, 669900, 755820, 788970, 803880, 821100, 828828, 895356, 896610, 948090, 985320, 986700, 1065900, 1123122, 1168860, 1184040, 1279080, 1331330 (list; graph; refs; listen; history; text; internal format)
OFFSET

1,1

LINKS

Amiram Eldar, Table of n, a(n) for n = 1..3000

MATHEMATICA

Select[Range[10^6],  Plus @@ Times @@@(f = FactorInteger[#]) == 2^Length@f &] (* Amiram Eldar, Dec 01 2019 *)

PROG

(PARI) sopfr(n, s, fac, i) = fac=factor(n); for(i=1, matsize(fac)[1], s=s+fac[i, 1]*fac[i, 2]); return(s);

isok(k) = sopfr(k) == 2^omega(k);

CROSSREFS

Cf. A001414, A034444.

Sequence in context: A262059 A153737 A078933 * A057645 A129060 A190127

Adjacent sequences:  A064026 A064027 A064028 * A064030 A064031 A064032

KEYWORD

nonn

AUTHOR

Jason Earls, Sep 12 2001

STATUS

approved

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Last modified December 8 20:37 EST 2021. Contains 349596 sequences. (Running on oeis4.)