a(n) = Sum_{1 <= x_1 <= x_2 <= ... <= x_n = n} gcd(x_1, x_2, ... , x_n).
A343553
a(n) = Sum_{1 <= x_1 <= x_2 <= ... <= x_n = n} gcd(x_1, x_2, ... , x_n).
Terms
- a(0) =1a(1) =3a(2) =8a(3) =26a(4) =74a(5) =287a(6) =930a(7) =3572a(8) =12966a(9) =49379a(10) =184766a(11) =710712a(12) =2704168a(13) =10427822a(14) =40123208a(15) =155289768a(16) =601080406a(17) =2334740919a(18) =9075135318a(19) =35352194658a(20) =137846990678a(21) =538302226835
External references
- oeis: A343553