A088387 in OEIS spf(n) is the prime corresponding to largest prime power factor of n, a(1)=1.
Most significant prime factor of n: If n = (p_1^e_1)(p_2^e_2)(p_3^e_3)... and max(p_1^e_1,p_2^e_2,...) = p_k^e_k then spf(n) = p_k.

Note:spf of 139..149 are 139, 7, 47, 71, 13, 2, 29, 73, 7, 37, 149
spf(140)==spf(147)==7
[619, 31, 3, 311, 89, 2, 5, 313, 19, 157, 37, 3,631]
spf(621)==spf(630)==3
[2503, 313, 167, 179, 109, 19, 193, 251, 3, 157, 359, 419, 503, 37, 839, 1259, 229, 3,2521]
spf(2511)==spf(2520)==3
so, spf(n) can NOT always as distinct prime factors for p[i]..p[i+1].