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 A062791 #23 May 29 2025 01:09:12
%S A062791 1,1,2,4,9,16,34,64,123,241,461,900,1715,3396,6423,12800,24309,48477,
%T A062791 92377,184500,352679,704969,1352077,2703168,5200290,10398883,20058174,
%U A062791 40113164,77558759,155110827,300540194,601067520,1166802646,2333581909,4537567606
%N A062791 Moebius transform of A001405 (binomial(n, floor(n/2))).
%H A062791 Alois P. Heinz, <a href="/A062791/b062791.txt">Table of n, a(n) for n = 1..1000</a>
%F A062791 a(n) = Sum_{d|n} A001405(n/d)*mu(d).
%e A062791 For n = 7, binomial(7,3) = 35, A001405(7/d) = {binomial(7,3), binomial(1,0)} = {35, 1}, mu(d) = {1, -1}, the sum is a(7) = 35 - 1 = 34.
%p A062791 with(numtheory):
%p A062791 a:= n-> add(binomial(d, iquo(d, 2))*mobius(n/d), d=divisors(n)):
%p A062791 seq(a(n), n=1..40); # _Alois P. Heinz_, Jul 09 2017
%t A062791 a[n_] := DivisorSum[n, Binomial[#, Floor[#/2]] * MoebiusMu[n/#] &]; Array[a, 35] (* _Amiram Eldar_, May 28 2025 *)
%o A062791 (PARI) a(n) = sumdiv(n, d, binomial(d, d\2) * moebius(n/d)); \\ _Amiram Eldar_, May 28 2025
%Y A062791 Cf. A001405, A007727, A062798.
%K A062791 nonn
%O A062791 1,3
%A A062791 _Labos Elemer_, Jul 19 2001
%E A062791 Offset corrected by _Eric Rowland_, Jul 09 2017