30171

Appears in sequences

• Crystal ball sequence for hexagonal close-packing.at n=20A007202
• T(n,n+3), array T given by A047020.at n=8A047028
• -21*zeta_K(-1), where K runs through the simplest cubic fields.at n=8A084711
• Indices of terms in A091074 which are prime numbers.at n=41A091076
• Number of 3 X 3 0..n symmetric arrays with all rows summing to floor(n*3/2).at n=39A213801