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A350961
a(n) = Sum_{k=1..n} 3^Omega(k).
4
1, 4, 7, 16, 19, 28, 31, 58, 67, 76, 79, 106, 109, 118, 127, 208, 211, 238, 241, 268, 277, 286, 289, 370, 379, 388, 415, 442, 445, 472, 475, 718, 727, 736, 745, 826, 829, 838, 847, 928, 931, 958, 961, 988, 1015, 1024, 1027, 1270, 1279, 1306, 1315, 1342, 1345, 1426, 1435, 1516, 1525, 1534, 1537, 1618
OFFSET
1,2
REFERENCES
Tenenbaum, G. (2015). Introduction to analytic and probabilistic number theory, 3rd ed., American Mathematical Soc. See page 59.
LINKS
MATHEMATICA
Accumulate[3^PrimeOmega[Range[100]]] (* Vaclav Kotesovec, Feb 16 2022 *)
PROG
(Python)
from sympy.ntheory.factor_ import primeomega
def A350961(n): return sum(3**primeomega(m) for m in range(1, n+1)) # Chai Wah Wu, Sep 07 2023
CROSSREFS
Cf. A001222 (Omega), A069205, A069212. Partial sums of A165824.
Sequence in context: A059014 A360800 A255650 * A166700 A266532 A160715
KEYWORD
nonn,easy
AUTHOR
N. J. A. Sloane, Feb 06 2022
STATUS
approved