0,4

36m^2+24m+7=(6m+2)^2+3 which is three more than a square

Table of n, a(n) for n=0..60.

36*a(n)^2+24*a(n)+7=A049423(n+1).

a(3)=-2 since 36*(-2)^2+24*(-2)+7=144-48+7=103 which is prime

This sequence and formula generate all but the first prime of the form k^2+3, i.e. A049423.

Sequence in context: A024683 A244017 A071528 * A089676 A334653 A230059

Adjacent sequences: A056899 A056900 A056901 * A056903 A056904 A056905

sign

Henry Bottomley, Jul 06 2000

approved