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A215283
Row sums of triangle A215200.
4
1, 1, 2, 2, 0, 2, 2, 0, 6, 2, 6, 0, 2, 4, 4, 8, 4, 0, 8, 0, 0, 2, 4, 0, 14, 6, 2, 0, -2, 4, 8, 0, 2, 4, 12, 12, 4, 6, 10, 0, 10, 4, 8, 0, 2, 4, 6, 0, 32, 2, 12, 0, 0, 2, 12, 0, 2, 2, 18, 0, 2, 8, 2, 32, 10, 8, 8, 0, 0, 4, 12, 0, -2, 10, 6, 0, 0, 4, 18, 0, 42
OFFSET
1,3
COMMENTS
The unsigned version of A215200 is A054521 which has as row sums the Euler totient function A000010.
LINKS
FORMULA
a(n) = Sum_{k=1..n} (n-k | k) where (i | j) is the Kronecker symbol.
MAPLE
f:= n -> add(numtheory:-jacobi(n-k, k), k=1..n); # Robert Israel, Mar 11 2018
MATHEMATICA
a[n_] := Sum[ KroneckerSymbol[n - k, k], {k, 1, n}]; Table[a[n], {n, 1, 81}] (* Jean-François Alcover, Jul 02 2013 *)
PROG
(Sage)
def A215200_row(n): return [kronecker_symbol(n-k, k) for k in (1..n)]
[sum(A215200_row(n)) for n in (1..81)]
CROSSREFS
KEYWORD
sign,look
AUTHOR
Peter Luschny, Aug 07 2012
STATUS
approved