login
A112599
Triangle where a(1,1) = 1, a(n,m) = number of terms of row (n-1) which are coprime to m.
5
1, 1, 1, 2, 2, 2, 3, 0, 3, 0, 4, 2, 0, 2, 2, 5, 0, 4, 0, 4, 0, 6, 1, 3, 1, 2, 1, 3, 7, 5, 4, 5, 7, 3, 7, 5, 8, 7, 7, 7, 5, 6, 5, 7, 7, 9, 7, 8, 7, 7, 7, 4, 7, 8, 5, 10, 7, 9, 7, 9, 6, 5, 7, 9, 6, 10, 11, 7, 6, 7, 8, 4, 8, 7, 6, 6, 11, 4, 12, 5, 9, 5, 12, 5, 9, 5, 9, 5, 10, 5, 12, 13, 9, 7, 9, 6, 6, 13, 9, 7
OFFSET
1,4
COMMENTS
GCD(m,0) is considered here to be m, so 0 is coprime to no positive integer but 1.
LINKS
EXAMPLE
Row 6 of the triangle is [5,0,4,0,4,0]. Among these terms there are 6 terms coprime to 1, 1 term coprime to 2, 3 terms coprime to 3, 1 term coprime to 4, 2 terms coprime to 5, 1 term coprime to 6 and 3 terms coprime to 7. So row 7 is [6,1,3,1,2,1,3].
1
1 1
2 2 2
3 0 3 0
4 2 0 2 2
5 0 4 0 4 0
6 1 3 1 2 1 3
7 5 4 5 7 3 7 5
8 7 7 7 5 6 5 7 7
9 7 8 7 7 7 4 7 8 5
MATHEMATICA
f[l_] := Block[{p, t}, p = l[[ -1]]; k = Length[p]; t = Table[ Sum[ If[GCD[p[[j]], n] == 1, 1, 0], {j, k}], {n, k + 1}]; Return[Append[l, t]]; ]; Flatten[Nest[f, {{1}}, 13]] (* Ray Chandler, Dec 24 2005 *)
CROSSREFS
Row sums are in A114718. - Klaus Brockhaus, Jun 01 2009
Sequence in context: A307296 A004489 A305384 * A347905 A308119 A307299
KEYWORD
nonn,tabl,look
AUTHOR
Leroy Quet, Dec 21 2005
EXTENSIONS
Extended by Ray Chandler, Dec 24 2005
STATUS
approved