A128970 a(n) is the n-th prime of the form n*x^2+1.

2, 19, 193, 101, 35281, 727, 2269, 18433, 15877, 7841, 247501, 10093, 35153, 727777, 47041, 33857, 2913733, 19603, 1076237, 486721, 806737, 55001, 1907713, 345601, 193601, 7581601, 1037233, 84701, 42599377, 337081, 3797501, 2654209

Offset

1,1

Links

Table of n, a(n) for n=1..32.

Example

a(6) is 727 because 6*1^2+1=7, 6*4^2+1=97, 6*5^2+1=151, 6*9^2+1=487, 6*10^2+1=601 and 6*11^2+1=727 are the first 6 primes of the form 6x^2+1.

Crossrefs

Sequence in context: A221904 A124262 A140781 * A218117 A145104 A114016

Adjacent sequences: A128967 A128968 A128969 * A128971 A128972 A128973

Keyword

nonn

Author

John L. Drost, Apr 28 2007

Status

approved