OFFSET
0,2
COMMENTS
a(16) does not exist because no earlier term has exactly 5 divisors. However, arbitrary modifications of the sequence's definition (such as letting a(n) = a(n-1) + 0 if no earlier term has the same number of divisors as n, or letting a(n) = a(n-1) + the largest earlier term with at most n divisors, etc.) would allow the sequence to be infinite in length.
EXAMPLE
9 has 3 divisors. So a(9) = a(8) + the largest earlier term with 3 divisors. a(3) = 4 is the only earlier term with 3 divisors, so a(9) = a(8) + 4 = 50.
CROSSREFS
KEYWORD
fini,full,nonn
AUTHOR
Leroy Quet, Jan 26 2007
STATUS
approved