A190391 Numbers with prime factorization pqrs^2t^2u^2.

900900, 1178100, 1261260, 1316700, 1392300, 1556100, 1593900, 1649340, 1843380, 1883700, 1949220, 1981980, 2009700, 2034900, 2102100, 2148300, 2178540, 2187900, 2231460, 2342340, 2375100, 2445300, 2463300, 2538900, 2564100, 2591820

Offset

1,1

Links

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

Will Nicholes, Prime Signatures

Mathematica

f[n_]:=Sort[Last/@FactorInteger[n]]=={1, 1, 1, 2, 2, 2}; Select[Range[3500000], f]

Prog

(PARI) list(lim)=my(v=List(), t1, t2, t3, t4, t5); forprime(p=2, sqrtint(lim\13860), t1=p^2; forprime(q=2, sqrtint(lim\(420*t1)), if(q==p, next); t2=q^2*t1; forprime(r=2, sqrtint(lim\(30*t2)), if(r==p || r==q, next); t3=r^2*t2; forprime(s=2, lim\(6*t3), if(s==p || s==q || s==r, next); t4=s*t3; forprime(t=2, lim\(2*t4), if(t==p || t==q || t==r || t==s, next); t5=t*t4; forprime(u=2, lim\t5, if(u==p || u==q || u==r || u==s || u==t, next); listput(v, t5*u))))))); Set(v) \\ Charles R Greathouse IV, Aug 25 2016

Crossrefs

Cf. A190388, A190390.

Sequence in context: A346281 A032429 A184456 * A154547 A357494 A209208

Adjacent sequences: A190388 A190389 A190390 * A190392 A190393 A190394

Keyword

nonn

Author

Vladimir Joseph Stephan Orlovsky, May 09 2011

Status

approved