This is a front-end for the Online Encyclopedia of Integer Sequences, made by Christian Perfect. The idea is to provide OEIS entries in non-ancient HTML, and then to think about how they're presented visually. The source code is on GitHub.
%I A350961 #18 Sep 07 2023 12:50:04
%S A350961 1,4,7,16,19,28,31,58,67,76,79,106,109,118,127,208,211,238,241,268,
%T A350961 277,286,289,370,379,388,415,442,445,472,475,718,727,736,745,826,829,
%U A350961 838,847,928,931,958,961,988,1015,1024,1027,1270,1279,1306,1315,1342,1345,1426,1435,1516,1525,1534,1537,1618
%N A350961 a(n) = Sum_{k=1..n} 3^Omega(k).
%D A350961 Tenenbaum, G. (2015). Introduction to analytic and probabilistic number theory, 3rd ed., American Mathematical Soc. See page 59.
%H A350961 Vaclav Kotesovec, <a href="/A350961/b350961.txt">Table of n, a(n) for n = 1..10000</a>
%t A350961 Accumulate[3^PrimeOmega[Range[100]]] (* _Vaclav Kotesovec_, Feb 16 2022 *)
%o A350961 (Python)
%o A350961 from sympy.ntheory.factor_ import primeomega
%o A350961 def A350961(n): return sum(3**primeomega(m) for m in range(1,n+1)) # _Chai Wah Wu_, Sep 07 2023
%Y A350961 Cf. A001222 (Omega), A069205, A069212. Partial sums of A165824.
%K A350961 nonn,easy
%O A350961 1,2
%A A350961 _N. J. A. Sloane_, Feb 06 2022