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A162194
Sum of divisors of nonprime number A018252(n).
3
1, 7, 12, 15, 13, 18, 28, 24, 24, 31, 39, 42, 32, 36, 60, 31, 42, 40, 56, 72, 63, 48, 54, 48, 91, 60, 56, 90, 96, 84, 78, 72, 124, 57, 93, 72, 98, 120, 72, 120, 80, 90, 168, 96, 104, 127, 84, 144, 126, 96, 144, 195, 114, 124, 140, 96, 168, 186, 121, 126, 224, 108, 132
OFFSET
1,2
COMMENTS
Also, 1 together with the numbers A073255.
LINKS
FORMULA
a(n) = A000203(A018252(n)).
MAPLE
with(NumberTheory): seq(`if`(isprime(n), NULL, sigma(n)), n = 1 .. 100); # Reza K Ghazi, Aug 28 2021
MATHEMATICA
Join[{1}, DivisorSigma[1, #]&/@Select[Range[100], CompositeQ]] (* Requires Mathematica version 10 or later *) (* Harvey P. Dale, May 27 2017 *)
PROG
(PARI) a = List(); for(n=1, 100, if(!isprime(n), listput(a, sigma(n)))); Vec(a) \\ Reza K Ghazi, Aug 28 2021
(SageMath) [sigma(n) for n in range(1, 101) if not is_prime(n)] # Reza K Ghazi Aug 28 2021
CROSSREFS
KEYWORD
easy,nonn
AUTHOR
Omar E. Pol, Jul 04 2009
STATUS
approved