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

 

Logo


Hints
(Greetings from The On-Line Encyclopedia of Integer Sequences!)
A057939 Number of prime factors of 5^n + 1 (counted with multiplicity). 0
2, 2, 4, 2, 3, 3, 4, 3, 6, 4, 5, 3, 4, 3, 7, 3, 4, 5, 5, 4, 10, 4, 4, 4, 5, 5, 10, 3, 4, 7, 5, 4, 9, 6, 7, 6, 5, 4, 8, 5, 6, 6, 6, 3, 10, 3, 5, 5, 7, 7, 10, 5, 5, 6, 7, 7, 9, 3, 6, 6, 6, 4, 16, 4, 8, 7, 3, 7, 9, 7, 5, 6, 5, 5, 13, 5, 9, 10, 6, 6, 14, 6, 5, 7, 9, 5, 9, 7, 5, 12, 8, 4, 10, 6, 9, 7, 7, 7, 12 (list; graph; refs; listen; history; text; internal format)
OFFSET

1,1

LINKS

Table of n, a(n) for n=1..99.

S. S. Wagstaff, Jr., Main Tables from the Cunningham Project.

S. S. Wagstaff, Jr., The Cunningham Project

FORMULA

a(n) = A057956(2n) - A057956(n) - T. D. Noe, Jun 19 2003

MATHEMATICA

PrimeOmega[5^Range[100]+1] (* Harvey P. Dale, Nov 27 2013 *)

CROSSREFS

Cf. A057934-A057941, A054992.

Cf. A057956.

Sequence in context: A238745 A092607 A221861 * A163371 A061338 A135714

Adjacent sequences:  A057936 A057937 A057938 * A057940 A057941 A057942

KEYWORD

nonn

AUTHOR

Patrick De Geest, Oct 15 2000.

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 October 18 15:41 EDT 2019. Contains 328162 sequences. (Running on oeis4.)