login
This site is supported by donations to The OEIS Foundation.

 

Logo


Hints
(Greetings from The On-Line Encyclopedia of Integer Sequences!)
A167189 Larger prime power associated with record gap in A167186. 2
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 (list; graph; refs; listen; history; text; internal format)
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

Lookup | Welcome | Wiki | Register | Music | Plot 2 | Demos | Index | Browse | More | WebCam
Contribute new seq. or comment | Format | Style Sheet | Transforms | Superseeker | Recent
The OEIS Community | Maintained by The OEIS Foundation Inc.

License Agreements, Terms of Use, Privacy Policy. .

Last modified March 19 04:23 EDT 2019. Contains 321311 sequences. (Running on oeis4.)