A centered heptagonal number is a centered figurate number that represents a heptagon with a dot in the center and all other dots surrounding the center dot in successive heptagonal layers. The centered heptagonal number for n is given by the formula
The first few centered heptagonal numbers are
1, 8, 22, 43, 71, 106, 148, 197, 253, 316, 386, 463, 547, 638, 736, 841, 953 (sequence A069099 in the OEIS)
A centered heptagonal prime is a centered heptagonal number that is prime. The first few centered heptagonal primes are
Due to parity, the centered heptagonal primes are in the form of or .
The centered heptagonal twin prime numbers are