Centered heptagonal number
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 Centered heptagonal prime. A centered heptagonal prime is a centered heptagonal number that is prime. The first few centered heptagonal primes are and centered heptagonal twin prime numbers are Centered heptagonal