OFFSET
1,2
COMMENTS
First differs from A106492 for n=64.
LINKS
Robert Israel, Table of n, a(n) for n = 1..10000
Chris Bispels, Muhammet Boran, Steven J. Miller, Eliel Sosis, and Daniel Tsai, v-Palindromes: An Analogy to the Palindromes, arXiv:2405.05267 [math.HO], 2024.
Daniel Tsai, A recurring pattern in natural numbers of a certain property, arXiv:2010.03151 [math.NT], 2020.
Daniel Tsai, A recurring pattern in natural numbers of a certain property, Integers (2021) Vol. 21, Article #A32.
EXAMPLE
For n = 18 = 2*3^2, a(18) = 2 + (3+2) = 7.
MAPLE
f:= proc(n) local t;
add(t[1]+t[2], t=subs(1=0, ifactors(n)[2]));
end proc:
map(f, [$1..100]); # Robert Israel, Oct 13 2020
MATHEMATICA
a[1] = 0; a[n_] := Plus @@ First /@ (f = FactorInteger[n]) + Plus @@ Select[Last /@ f, # > 1 &]; Array[a, 100] (* Amiram Eldar, Oct 08 2020 *)
PROG
(PARI) a(n) = my(f=factor(n)); vecsum(f[, 1]) + sum(k=1, #f~, if (f[k, 2]!=1, f[k, 2]));
CROSSREFS
KEYWORD
nonn
AUTHOR
Michel Marcus, Oct 08 2020
STATUS
approved