A382066 a(n) = Sum_{k=1..prime(n)-1} (-k/prime(n)) * 3^(k-1) / 2, where (p/q) is the Legendre symbol of p and q.

1, 8, 151, 8083, 70568, 8910416, 39392803, 7701058213, 2325990648824, 43563061207573, 19999898090377928, 2566793589644124992, 10627327735475477203, 2179055220073884519235, 630486036620986837882904, 646895254841829205782412249, 5802709167332592724735012664

Offset: 2

Author

Steven Lu, Mar 14 2025

Keywords

• nonn

Comments

All terms are integers since Sum_{k=1..p-1} (-k/p) * 3^(k-1) is even for any odd prime p.

Links

• Steven Lu, Table of n, a(n) for n = 2..316

Programs

Mathematica

Table[Sum[KroneckerSymbol[-i, q] 3^(i - 1), {i, q - 1}], {q, Prime /@ Range[2, 18]}]/2