OFFSET
1,1
COMMENTS
a(1) = 1, a(n+1) = a(n) + tau(a(n)) gives A064491.
EXAMPLE
a(4) = 72 and tau(72)= 12, hence a(5) = 72*12= 864.
MATHEMATICA
NestList[# DivisorSigma[0, #]&, 2, 20] (* Harvey P. Dale, Apr 23 2023 *)
PROG
(PARI) for(n=1, 16, if(n==1, a=2, a*=numdiv(a)); print(a); )
CROSSREFS
KEYWORD
nonn
AUTHOR
Amarnath Murthy, Jul 06 2003
EXTENSIONS
More terms from Ray Chandler, Jul 16 2003
STATUS
approved