OFFSET
1,1
COMMENTS
Here 5-infinitary-sigma(a) means sum of 5-infinitary-divisor of a. If n=Product p_i^r_i and d=Product p_i^s_i, each s_i has a digit a<=b in its 5-ary expansion everywhere that the corresponding r_i has a digit b, then d is a 5-infinitary-divisor of n.
Is it certain that 308474880 is the 6th term? M. F. Hasler, Nov 20 2010
FORMULA
{n: A097863(n) = 2*n}.
EXAMPLE
Factorizations: 2*3, 2^2*7, 2^4*31, 2^5*3^3*5*11, 2^5*3^2*7*11*13, 2^10*3*5*7*19*151
CROSSREFS
KEYWORD
nonn
AUTHOR
EXTENSIONS
Missing a(4) inserted by R. J. Mathar, Nov 20 2010
STATUS
approved