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A071958
Numbers k such that Sum_{i=0..k} K(k, i) < 0 where K(x, y) is the Kronecker symbol (x/y).
2
67, 99, 115, 147, 163, 187, 267, 275, 283, 307, 315, 355, 379, 403, 427, 475, 507, 523, 531, 595, 619, 643, 675, 747, 763, 787, 883, 907, 931, 947, 955, 975, 1003, 1027, 1107, 1123, 1147, 1179, 1203, 1267, 1275, 1347, 1363, 1387, 1395, 1435, 1467, 1475
OFFSET
1,1
LINKS
MATHEMATICA
f[n_] := Sum[ KroneckerSymbol[n, k], {k, 0, n}]; Select[ Range@ 1500, f[#] < 0 &] (* Robert G. Wilson v, Mar 21 2015 *)
PROG
(PARI) for(n=1, 1800, if(sum(i=0, n, kronecker(n, i)) < 0, print1(n, ", ")))
(SageMath)
print([n for n in range(999) if sum(kronecker(n, k)
for k in range(n + 1)) < 0]) # Peter Luschny, May 16 2024
CROSSREFS
Cf. A071961.
Sequence in context: A260806 A180557 A127732 * A128197 A140541 A136077
KEYWORD
easy,nonn
AUTHOR
Benoit Cloitre, Jun 16 2002
EXTENSIONS
Summation range set to {i=0..k} by Peter Luschny, May 16 2024
STATUS
approved