a(1) = a(2) = 1; for n > 2, a(n+2) = Sum_{d|n} tau(n/d)*a(d), where tau = number of divisors (A000005).
A319133
a(1) = a(2) = 1; for n > 2, a(n+2) = Sum_{d|n} tau(n/d)*a(d), where tau = number of divisors (A000005).
Terms
- a(0) =1a(1) =1a(2) =1a(3) =3a(4) =3a(5) =8a(6) =5a(7) =16a(8) =7a(9) =29a(10) =12a(11) =41a(12) =14a(13) =76a(14) =16a(15) =92a(16) =28a(17) =142a(18) =30a(19) =185a(20) =32a(21) =268a(22) =48a(23) =298a(24) =50a(25) =466a(26) =59a(27) =500a(28) =80a(29) =683
External references
- oeis: A319133