OFFSET
1,1
LINKS
Anders Hellström, Table of n, a(n) for n = 1..1000
MATHEMATICA
a[1] = a[2] = 2; a[n_] := a[n] = a[n - 1] + FactorInteger[a[n - 2]][[-1, 1]]; Table[a@ n, {n, 46}] (* Michael De Vlieger, Nov 16 2015 *)
nxt[{a_, b_}]:={b, b+FactorInteger[a][[-1, 1]]}; Transpose[NestList[nxt, {2, 2}, 50]][[1]] (* Harvey P. Dale, Nov 22 2015 *)
PROG
(PARI) gpf(n)=my(f=factor(n)[, 1]); f[#f];
first(m)=my(v=vector(m)); v[1]=2; v[2]=2; for(i=3, m, v[i]=v[i-1]+gpf(v[i-2])); v
(Haskell)
a258125 n = a258125_list !! (n-1)
a258125_list = 2 : 2 : zipWith (+)
(map a006530 a258125_list) (tail a258125_list)
-- Reinhard Zumkeller, Nov 17 2015
CROSSREFS
KEYWORD
nonn
AUTHOR
Anders Hellström, Nov 16 2015
STATUS
approved