A118103 -id:A118103 - cp's OEIS frontend

A118104 Primes in A118103.

2, 47, 67, 173, 229, 257, 877, 1009, 1031, 1097, 1163, 1669, 1721, 1747, 1877, 2731, 2791, 2851, 2971, 3001, 3061, 3121, 3181, 3271, 3301, 3331, 3361, 3391, 3407, 3583, 3631, 3727, 3823, 3919, 3967, 4079, 4111, 4127, 4159, 4597, 4733, 4801, 4903, 4937

Offset: 1

Franklin T. Adams-Watters, Apr 12 2006

nonn

Primes are relatively scarce in A118103 because there is often a common factor between a(n) and the difference a(n)-a(n-1); if this same difference applies to the next term, it will also be composite.

Charlie Neder, Table of n, a(n) for n = 1..1000

Cf. A118103, A118105.

A118105 Greatest common divisor of n and the terms in A118103 whose difference is n.

Original entry on oeis.org

1, 1, 2, 3, 2, 1, 3, 1, 8, 3, 2, 1, 4, 1, 2, 1, 1, 1, 2, 19, 1, 3, 2, 1, 1, 25, 2, 1, 1, 1, 10, 1, 1, 1, 2, 5, 1, 1, 2, 3, 5, 1, 2, 1, 1, 5, 2, 1, 3, 1, 10, 1, 4, 1, 6, 5, 4, 1, 2, 1, 20, 1, 2, 3, 4, 5, 2, 1, 4, 1, 1, 1, 2, 1, 1, 1, 4, 1, 1, 1, 2, 1, 1, 1, 4, 1, 1, 1, 2, 1, 1, 1, 1, 1, 1, 1, 3, 1, 1, 1, 1, 1, 1

Offset: 0