A053998 Smallest prime in n-th shell of prime spiral.

2, 3, 29, 101, 229, 421, 673, 1013, 1429, 1889, 2441, 3089, 3821, 4639, 5521, 6491, 7577, 8741, 9941, 11329, 12757, 14341, 15881, 17623, 19477, 21397, 23333, 25471, 27743, 30059, 32441, 34871, 37507, 40237, 42953, 46021

Offset: 0

Author

Enoch Haga, Apr 06 2000

Keywords

• easy
• nonn

Examples

			a(2)=3 because it is the first prime in shell 1 (prime 2 is in shell 0).