A167188 - OEIS

%I #11 Jul 27 2024 13:54:57

%S 1,4,9,16,32,81,128,169,361,1024,1369,2401,4489,5329,6889,8192,12769,

%T 19683,32768,39601,44521,85849,177241,218089,262144,279841,436921,

%U 597529,744769,786769,1142761,1771561,5340721,6135529,8826841,10699441,17447329,18464209

%N Smaller prime power associated with record gap in A167186.

%H Donovan Johnson, <a href="/A167188/b167188.txt">Table of n, a(n) for n = 1..200</a>

%e 32 is in the sequence since the gap between 32 and the next prime power, 49, is greater than any previous gap.

%o (PARI) isA025475(n) = (omega(n) == 1 & !isprime(n)) || (n == 1)

%o d_max=0;n_prev=1;for(n=2,32e6,if(isA025475(n),d=n-n_prev;if(d>d_max,print(n_prev);d_max=d);n_prev=n))

%Y Larger prime power: A167189.

%Y Record gaps between nonprime prime powers: A167186.

%Y Gaps between nonprime prime powers: A053707.

%Y List of nonprime prime powers: A025475.

%K nonn

%O 1,2

%A _Michael B. Porter_, Nov 01 2009