OFFSET
1,1
LINKS
Alois P. Heinz, Table of n, a(n) for n = 1..10000
FORMULA
MAPLE
b:= proc(n) option remember; `if`(n=1, 1,
b(n-1) +nops(ifactors(n)[2]))
end:
a:= n-> b(ithprime(n)):
seq(a(n), n=1..60); # Alois P. Heinz, Jun 06 2019
MATHEMATICA
b[n_] := b[n] = If[n == 1, 1, b[n-1] + PrimeNu[n]];
a[n_] := b[Prime[n]];
Array[a, 60] (* Jean-François Alcover, Nov 27 2020, after Alois P. Heinz *)
PROG
(Haskell)
-- expected to be part of A027748
a027748_list = concat (map a027748_row [1..])
minIdx [] _ = []
minIdx _ [] = []
minIdx (a:as) (b:bs)
| a == b = 1 : (map succ (minIdx as bs))
| otherwise = map succ (minIdx as (b:bs))
a308495_list = minIdx a027748_list a000040_list
a308495 n = a308495_list !! (n-1)
(PARI) a(n) = 1 + sum(k=1, prime(n), omega(k)); \\ Michel Marcus, Jun 05 2019
CROSSREFS
KEYWORD
nonn
AUTHOR
Peter Dolland, Jun 01 2019
STATUS
approved