A167189 Larger prime power associated with record gap in A167186.

4, 8, 16, 25, 49, 121, 169, 243, 512, 1331, 1681, 2809, 4913, 6241, 7921, 9409, 14641, 22201, 36481, 44521, 49729, 94249, 185761, 226981, 271441, 292681, 452929, 619369, 769129, 822649, 1181569, 1852321, 5442889, 6265009, 8994001, 10883401, 17648401, 18722929

Offset

1,1

Links

Donovan Johnson, Table of n, a(n) for n = 1..200

Example

49 is in the sequence since the gap between it the previous prime power, 32, is greater than any previous gap.

Prog

(PARI) isA025475(n) = (omega(n) == 1 & !isprime(n)) | (n == 1)
d_max=0; n_prev=1; for(n=2, 32e6, if(isA025475(n), d=n-n_prev; if(d>d_max, print(n); d_max=d); n_prev=n))

Crossrefs

Smaller prime power is in A167188.

Record gaps between nonprime prime powers: A167186.

Gaps between nonprime prime powers: A053707.

List of nonprime prime powers: A025475.

Sequence in context: A003451 A277029 A013934 * A050470 A138501 A096296

Adjacent sequences: A167186 A167187 A167188 * A167190 A167191 A167192

Keyword

nonn

Author

Michael B. Porter, Nov 01 2009

Status

approved