OFFSET
1,1
COMMENTS
Subsequence of A025475. The missing terms of A025475 are 1 and prime powers q^n for which there is a smaller prime power p^m with q^n-q <= p^m-p, i.e., q^n = p^m+d for some d <= q-p. The first cases: 9 = 3^2 = 2^3+1, 529 = 23^2 = 2^9+17, 2197 = 13^3 = 3^7+10, 2209 = 47^2 = 3^7+22, 6889 = 83^2 = 19^3+30. - Jens Kruse Andersen, Aug 26 2014
LINKS
Jens Kruse Andersen, Table of n, a(n) for n = 1..10000
PROG
(PARI) k=2; for(n=0, 10506, k=k-1; r=k+1; until(vecmax(vector(#f[, 1], i, f[i, 1]^f[i, 2]))>vecmax(f[, 1])+n, k++; f=factor(k)); if(k>r, print1(k, ", ")));
CROSSREFS
KEYWORD
nonn
AUTHOR
Arkadiusz Wesolowski, Aug 23 2014
STATUS
approved