a(n) is the smallest prime q such that, for the previous prime p and the following prime r, the fraction (q-p)/(r-q) has denominator n (or 0, if such a prime does not exist).

A168253

a(n) is the smallest prime q such that, for the previous prime p and the following prime r, the fraction (q-p)/(r-q) has denominator n (or 0, if such a prime does not exist).

Terms

    a(0) =5a(1) =3a(2) =23a(3) =89a(4) =139a(5) =199a(6) =113a(7) =1933a(8) =523a(9) =3089a(10) =1129a(11) =1669a(12) =2477a(13) =2971a(14) =4297a(15) =5591a(16) =1327a(17) =28351a(18) =30593a(19) =19333a(20) =16141a(21) =36389a(22) =81463a(23) =28229a(24) =31907a(25) =19609a(26) =35617a(27) =82073a(28) =44293a(29) =102701

External references