A127772 Row sums of inverse of number triangle A(n,k) = 1/Euler_phi(n+1) if k <= n <= 2k, 0 otherwise.

1, 1, 1, 1, 2, -1, 4, -1, 2, 0, 6, -7, 8, -2, 2, -1, 8, -8, 12, -10, 4, 4, 12, -21, 12, 0, 6, -8, 16, -18, 22, -15, 4, 4, 8, -20, 24, -6, 6, -18, 24, -24, 30, -18, 4, 10, 24, -51, 26, -10, 12, -8, 28, -28, 22, -24, 12, 8, 30, -60

Offset

0,5

Links

Table of n, a(n) for n=0..59.

Crossrefs

Row sums of A127771.

Sequence in context: A140168 A059119 A305333 * A086256 A227964 A057550

Adjacent sequences: A127769 A127770 A127771 * A127773 A127774 A127775

Keyword

sign

Author

Paul Barry, Jan 28 2007

Status

approved