OFFSET
1,2
LINKS
Michael De Vlieger, Table of n, a(n) for n = 1..7154
MATHEMATICA
Nest[Append[#1, If[EvenQ@ Last[#1], Last[#1]/2, GCD[Last[#1], #2]*Last[#1] + DivisorSigma[0, #2]]] & @@ {#, Length[#]} &, {1}, 52] (* Michael De Vlieger, Mar 20 2022 *)
PROG
(PARI) lista(nn) = my(va = vector(nn)); va[1] = 1; for (n=2, nn, va[n] = if (va[n-1]%2, gcd(va[n-1], n-1)*va[n-1] + numdiv(n-1), va[n-1]/2); ); va; \\ Michel Marcus, Mar 21 2022
CROSSREFS
KEYWORD
nonn
AUTHOR
Ctibor O. Zizka, Jan 07 2008
EXTENSIONS
Name and terms a(25) and following corrected by Jon E. Schoenfield, Mar 20 2022
STATUS
approved