A190462 Numbers with prime factorization pqrstu^2v^2.

3063060, 3423420, 4144140, 4476780, 5105100, 5225220, 5290740, 5419260, 5585580, 5705700, 6056820, 6404580, 6666660, 6832980, 6906900, 7147140, 7158060, 7304220, 7387380, 7461300, 7636860, 7657650, 7747740, 7987980, 8075340, 8163540, 8314020, 8468460

Offset: 1

Author

Vladimir Joseph Stephan Orlovsky, May 10 2011

Keywords

• nonn

Links

• T. D. Noe, Table of n, a(n) for n = 1..1000
• Will Nicholes, Prime Signatures

Crossrefs

Cf. A190390, A190391, A190316.

Programs

Mathematica

f[n_]:=Sort[Last/@FactorInteger[n]]=={1,1,1,1,1,2,2}; Select[Range[6000000],f]

PARI

list(lim)=my(v=List(),t1,t2,t3,t4,t5,t6); forprime(p1=2,sqrtint(lim\60060), t1=p1^2; forprime(p2=2,sqrtint(lim\(2310*t1)), if(p2==p1, next); t2=p2^2*t1; forprime(p3=2,lim\(210*t2), if(p3==p1 || p3==p2, next); t3=p3*t2; forprime(p4=2,lim\(30*t3), if(p4==p1 || p4==p2 || p4==p3, next); t4=p4*t3; forprime(p5=2,lim\(6*t4), if(p5==p1 || p5==p2 || p5==p3 || p5==p4, next); t5=p5*t4; forprime(p6=2,lim\(2*t5), if(p6==p1 || p6==p2 || p6==p3 || p6==p4 || p6==p5, next); t6=p6*t5; forprime(p7=2,lim\t6, if(p7==p1 || p7==p2 || p7==p3 || p7==p4 || p7==p5 || p7==p6, next); listput(v, t6*p7)))))))); Set(v) \\ Charles R Greathouse IV, Aug 25 2016

Extensions

Extended by T. D. Noe, May 10 2011