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 A280131 #13 Sep 08 2022 08:46:18
%S A280131 1,2,4,6,10,14,20,28,40,56,66,98,110,146,210,274,290,434,452,708,852,
%T A280131 952,974,1998,2078,2222,2438,3302,3330,7426,7456,8480,8880,9136,9712,
%U A280131 23536,23572,23896,24472,40856,40896,61632,61674,65674,74890,75374,75420
%N A280131 Partial sums of A029940 (Product_{d|n} phi(d)).
%C A280131 phi(n) is the number of totatives of n (A000010).
%H A280131 Robert Israel, <a href="/A280131/b280131.txt">Table of n, a(n) for n = 1..10000</a>
%F A280131 a(n) = Sum_{i=1..n} A029940(i).
%p A280131 A029940:= [seq(mul(numtheory:-phi(d),d=numtheory:-divisors(n)),n=1..100)]:
%p A280131 ListTools:-PartialSums(A029940); # _Robert Israel_, Jan 11 2017
%t A280131 Accumulate@ Array[Product[EulerPhi@ d, {d, Divisors@ #}] &, 47] (* _Michael De Vlieger_, Dec 27 2016 *)
%o A280131 (Magma) [&+[&*[EulerPhi(d): d in Divisors(k)]: k in [1..n]]: n in [1..100]]
%Y A280131 Cf. A000010, A029940, A232533 (partial sums of A057661), A280132 (partial products of A029940).
%K A280131 nonn
%O A280131 1,2
%A A280131 _Jaroslav Krizek_, Dec 27 2016