Hello Math-Fun, I was playing with a(n) being the remainder of the division by a(n+1) of a(n+2), with all terms prime. I've found this succession of primes, but I don't know if this is the lexico first such seq: S = 2,3,5,23,97,1187,14341,57073,... I found empirically by hand the last three terms because of this: the biggest factor that multiplies 5 to produce 3 as remainder is 4 (indeed, 23-4*5=3); the biggest factor that multiplies 23 to produce 97 as remainder is 4 (indeed, 97-4*23=5); the biggest factor that multiplies 97 to produce 23 as remainder is 12 (indeed, 1187-12*97=23); the biggest factor that multiplies 1187 to produce 97 as remainder is 12 (indeed, 14341-12*1187=97). Then, seing the pattern 4, 4, 12, 12,... I tried to multiply by 36... and got a hit: indeed 14341*36+1187 = 57073 which is prime. Any thoughts? à+ É. Catapulté de mon aPhone