A215696 a(n)=smallest positive k>n+2 such that k*n+1 is a square.

8, 12, 8, 12, 16, 20, 24, 15, 32, 36, 40, 24, 48, 52, 24, 33, 64, 68, 72, 42, 40, 84, 88, 35, 96, 100, 104, 60, 112, 56, 120, 69, 56, 132, 48, 78, 144, 148, 72, 60, 160, 72, 168, 96, 91, 180, 184, 63, 192, 196, 88, 114, 208, 212, 105, 85, 104, 228, 232, 84

Offset: 1

Author

Zak Seidov, Aug 21 2012

Keywords

• nonn

Comments

For any n and k=n+2, 1+k*n=(n+1)^2, so here we consider the case k>n+2. Cases kA076942, A215653.

Links

• Zak Seidov, Table of n, a(n) for n = 1..1000

Crossrefs

Cf. A076942, A215653.

Programs

PARI

for(n=1,100,k=n+3;while(!issquare(1+k*n),k++);print1(k","))