OFFSET
2,1
COMMENTS
6 = A007357(1) is only squarefree infinitary perfect number. In consequence, a(n)>=4 for n>1.
An irregular table with the infinitary divisors of A007357(n) which are also perfect squares starts in row n>=1 as
1;
1,4;
1,9;
1,9,16,144;
1,16,81,1296;
1,4,9,16,25,36,64,100,144,225,400,576,900,1600,3600,14400;
1,4,16,64,81,324,1296,5184;
1,9,256,2304;
1,16,25,49,81,400,784,1225,1296,2025,3969,19600,32400,63504,99225,1587600;
1,4,16,25,49,64,81,100,196,324,400,784,1225,1296,1600,2025,3136,3969,4900,...
1,81,256,20736;
The current sequence consists of the second column of this table.
CROSSREFS
KEYWORD
nonn
AUTHOR
Vladimir Shevelev, Feb 28 2011
STATUS
approved