A325380 Numbers k in A228058 such that also A001065(k) is in A228058.

801, 1377, 1773, 2525, 3725, 4689, 4753, 6309, 6425, 7209, 7677, 8577, 8957, 9477, 11133, 11225, 11493, 11925, 12393, 12429, 12789, 13077, 15381, 15777, 18873, 19269, 19845, 20025, 20629, 21213, 24201, 26073, 26721, 28037, 28989, 29277, 29961, 30037, 30213, 31925, 32553, 33273, 34425, 34677, 36369, 36441, 38725, 39249, 40329

Offset: 1

Author

Antti Karttunen, Apr 22 2019

Keywords

• nonn

Comments

If any odd perfect number exists, then it must occur in this sequence.

Links

• Antti Karttunen, Table of n, a(n) for n = 1..10000
• Index entries for sequences where any odd perfect numbers must occur

Crossrefs

Cf. A001065, A228058, A325377.

Programs

PARI

A001065(n) = (sigma(n)-n);
isA228058(n) = if(!(n%2)||(omega(n)<2),0,my(f=factor(n),y=0); for(i=1,#f~,if(1==(f[i,2]%4), if((1==y)||(1!=(f[i,1]%4)),return(0),y=1), if(f[i,2]%2, return(0)))); (y));
k=0; n=0; while(k<100,n++; if(isA228058(n)&&isA228058(A001065(n)), k++; print1(n,", ")));