A064623 Primitive subsequence of A066031: terms of A066031 which are not a multiple of some previous terms.

30, 70, 84, 105, 231, 234, 260, 286, 456, 528, 532, 627, 646, 805, 897, 1116, 1122, 1275, 1364, 1581, 1665, 1798, 1924, 2064, 2150, 2275, 2565, 2632, 2958, 2967, 3055, 3213, 3339, 3526, 3861, 4070, 4543, 4824, 5025, 5152, 5487, 5658, 5840, 6164, 6461

Offset: 1

Author

Robert G. Wilson v and Vladeta Jovovic, Dec 12 2001

Keywords

• nonn

Links

• Charles R Greathouse IV, Table of n, a(n) for n = 1..10000

Programs

Mathematica

a = {30}; Do[ If[ IntegerQ[ n / Apply[ Plus, First[ Transpose[ FactorInteger[n]]]]] && Mod[ n, n - EulerPhi[n]] != 0 && First[ Union[ Mod[n, a]]] != 0, a = Append[a, n]], {n, 1, 10000} ]; a

PARI

f(n)=my(f=factor(n)[,1]); #f[,1]>1 && n%sum(i=1,#f,f[i])==0
list(lim)=my(v=List(),p=2);forprime(q=p+1,nextprime(lim),for(n=p+1,q-1, if(f(n),for(i=1,#v,if(n%v[i]==0,next(2)));listput(v,n)));p=q);Vec(v) \\ Charles R Greathouse IV, Sep 08 2012