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A109958
Concatenate n and the sum of primes dividing n (counting multiplicity).
2
10, 22, 33, 44, 55, 65, 77, 86, 96, 107, 1111, 127, 1313, 149, 158, 168, 1717, 188, 1919, 209, 2110, 2213, 2323, 249, 2510, 2615, 279, 2811, 2929, 3010, 3131, 3210, 3314, 3419, 3512, 3610, 3737, 3821, 3916, 4011, 4141, 4212, 4343, 4415, 4511, 4625, 4747
OFFSET
1,1
LINKS
FORMULA
a(n) = 10^(A055652(A001414(n)))*n+A001414(n). - Robert Israel, Jun 26 2018
MAPLE
f:= proc(n) local q;
q:= add(t[1]*t[2], t=ifactors(n)[2]);
10^(1+ilog10(q))*n+q
end proc:
f(1):= 10:
map(f, [$1..100]); # Robert Israel, Jun 26 2018
MATHEMATICA
pr[{a_, b_}]:=a*b; Join[{10}, Table[FromDigits[Flatten[IntegerDigits[Join[{n}, {Total[pr/@FactorInteger[n]]}]]]], {n, 2, 47}]] (* James C. McMahon, Apr 02 2024 *)
CROSSREFS
KEYWORD
easy,nonn,base
AUTHOR
Jason Earls, Jul 06 2005
STATUS
approved