

A114380


Largest prime (or prime power) that divides any number between the primes p(n) and p(n+1).


0



4, 3, 9, 4, 16, 9, 11, 27, 5, 32, 19, 7, 23, 49, 29, 5, 64, 23, 9, 37, 81, 43, 47, 49, 17, 53, 27, 37, 125, 128, 67, 23, 73, 25, 31, 81, 83, 169, 89, 9, 61, 64, 97, 11, 103, 109, 113, 19, 29, 79, 16, 243, 256, 131, 89, 27, 137, 139, 47, 289
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OFFSET

2,1


LINKS

Table of n, a(n) for n=2..61.


EXAMPLE

a(4) = 9 because, of the numbers between 7 (= p(4)) and 11 (= p(5)), 9 has the largest prime, or primetoapower, divisor (namely, itself). a(13) = 7 because only 42 lies between 41 (= p(13)) and 43 (= p(14)) and its largest prime divisor is 7.


PROG

(PARI) a(n) = {ppmax = 1; for (i = prime(n)+1, prime(n+1)1, f = factor(i); for (j = 1, #f~, ppmax = max(ppmax, f[j, 1]^f[j, 2]); ); ); ppmax; } \\ Michel Marcus, Aug 25 2013


CROSSREFS

Sequence in context: A074123 A016704 A131896 * A293130 A103825 A073238
Adjacent sequences: A114377 A114378 A114379 * A114381 A114382 A114383


KEYWORD

easy,nonn


AUTHOR

Greg Huber, Feb 10 2006


EXTENSIONS

More terms from Joseph Pedersen (jmp456(AT)psu.edu), Apr 27 2006


STATUS

approved



