OFFSET
0,8
COMMENTS
See A374385.
FORMULA
EXAMPLE
P(0,x) = x^0; P(1,x) = x^0 - x^1; P(2,x) = x^0 + x^1; P(3,x) = x^0 + x^1 + x^2; P(4,x) = x^0 + x^1; P(5,x) = x^0 + x^1 + x^2 + x^3 + x^4; ...
The irregular triangle a(n,m) begins:
n\m 0 1 2 3 4 5 6 7 8 9 10 11 12 ...
0: 0
1: 0 1
2: 0 1
3: 0 1 2
4: 0 1
5: 0 1 2 3 4
6: 0 1 2
7: 0 1 2 3 4 5 6
8: 0 1
9: 0 1 2
10: 1 2 3 4
11: 0 1 2 3 4 5 6 7 8 9 10
12: 0 1 2
13: 0 1 2 3 4 5 6 7 8 9 10 11 12
14: 0 1 2 3 4 5 6
15: 0 1 3 4 5 7 8
16: 0 1
...
MATHEMATICA
nn = 17; f[n_] := DivisorSum[n, MoebiusMu[#] # &]; Flatten[Table[Exponent[Denominator[Sum[Sum[f[GCD[n, k]]*x^(n*h + k), {k, 1, n}], {h, 0, Infinity}]], x, List], {n, 0, nn}]]
CROSSREFS
KEYWORD
nonn,tabl
AUTHOR
Mats Granvik, Jul 07 2024
STATUS
approved