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

 

Logo


Hints
(Greetings from The On-Line Encyclopedia of Integer Sequences!)
A077258 Least number which can be represented by the difference between two successive prime powers of prime numbers (A076707) in just n ways. 2
1, 4, 6888, 4920, 187117320 (list; graph; refs; listen; history; text; internal format)
OFFSET

1,2

LINKS

Table of n, a(n) for n=1..5.

EXAMPLE

1 = 9-8, 4 = 8-4 & 125-121, 6888 = 332929 - 326041 = 744769 - 737881 = 2968729 - 2961841, 4920 = 44521 - 39601 = 63001 - 58081 = 380689 - 375769 = 1515361 - 1510441 and

187117320 = 9725896737769 - 9725709620449 = 21883150711249 - 21882963593929 = 60786363426721 - 60786176309401 = 243145173030769 - 243144985913449 = 2188305808807561 - 2188305621690241.

MATHEMATICA

pp = Sort[ Flatten[ Table[ Prime[n]^Prime[i], {n, 1, PrimePi[ Sqrt[10^16]]}, {i, 1, PrimePi[ Floor[ Log[ Prime[n], 10^16]]]}]]]; l = Length[pp]; b = Sort[ Take[pp, -l + 1] - Take[pp, l - 1]];

CROSSREFS

Cf. A053810, A075308, A076707, A077257.

Sequence in context: A046360 A079232 A137045 * A272165 A304994 A058440

Adjacent sequences:  A077255 A077256 A077257 * A077259 A077260 A077261

KEYWORD

more,nonn

AUTHOR

Zak Seidov and Robert G. Wilson v, Oct 31 2002

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 13:34 EDT 2019. Contains 321330 sequences. (Running on oeis4.)