Irregular triangle read by rows: T(n,k) is the number of primitive (period n) periodic palindromes using exactly k different symbols, 1 <= k <= 1 + floor(n/2).
A327878
Irregular triangle read by rows: T(n,k) is the number of primitive (period n) periodic palindromes using exactly k different symbols, 1 <= k <= 1 + floor(n/2).
Terms
- a(0) =1a(1) =0a(2) =1a(3) =0a(4) =2a(5) =0a(6) =3a(7) =3a(8) =0a(9) =6a(10) =6a(11) =0a(12) =7a(13) =21a(14) =12a(15) =0a(16) =14a(17) =36a(18) =24a(19) =0a(20) =18a(21) =90a(22) =132a(23) =60a(24) =0a(25) =28a(26) =150a(27) =240a(28) =120a(29) =0
External references
- oeis: A327878