| 1234567891011121314151617181920212223242526 |
- #!/usr/bin/ruby
- # Number n such that omega(sigma(n,n)) = bigomega(sigma(n,n))
- # Known terms:
- # 1, 2, 4, 5, 8, 9, 12, 13, 16, 20, 22, 25, 29, 32, 36, 37, 38, 40, 41, 44, 48, 49, 58, 61, 62, 64, 68, 72, 73, 76, 80, 88, 92, 96, 98, 101, 104, 109, 112, 113, 116, 117, 118
- # Inspired by:
- # https://oeis.org/A352420
- include("../../../factordb/auto.sf")
- func a(n) {
- var f = sigma_factors(n, n)
- #var f = sigma_factors_symbolic(n, n)
- f.map { FF_factordb(_) }.flat
- }
- for n in (1..1000) {
- var f = a(n)
- if (f.len == f.uniq.len) {
- print(n, ", ")
- }
- }
|
