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

 

Logo


Hints
(Greetings from The On-Line Encyclopedia of Integer Sequences!)
A005603 Chains of length n of nearly doubled primes.
(Formerly M4766)
12
11, 7, 2, 2131, 1531, 385591, 16651, 15514861, 857095381, 205528443121, 1389122693971, 216857744866621, 758083947856951, 107588900851484911, 69257563144280941 (list; graph; refs; listen; history; text; internal format)
OFFSET

1,1

COMMENTS

Complete Cunningham chain of the second kind.

REFERENCES

N. J. A. Sloane and Simon Plouffe, The Encyclopedia of Integer Sequences, Academic Press, 1995 (includes this sequence).

LINKS

Table of n, a(n) for n=1..15.

G. Löh, Long chains of nearly doubled primes, Math. Comp., 53 (1989), 751-759.

C. K. Caldwell, Cunningham chain.

CROSSREFS

A064812 is a better version.

Cf. (A005382 and A005383), A057326, A057327, A057328, A057329, A057330, A005602.

Sequence in context: A241308 A038320 A010185 * A109828 A048981 A132361

Adjacent sequences:  A005600 A005601 A005602 * A005604 A005605 A005606

KEYWORD

nonn

AUTHOR

N. J. A. Sloane.

EXTENSIONS

6th term corrected from 385591 on Feb 23 1995, at Robert G. Wilson v's suggestion

a(14) and a(15) found by Paul Jobling (Paul.Jobling(AT)WhiteCross.com) [Oct 23 2000]

a(6) reverted to original value by Sean A. Irvine, Jul 10 2016

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 | More pages
The OEIS Community | Maintained by The OEIS Foundation Inc.

License Agreements, Terms of Use, Privacy Policy .

Last modified February 25 10:56 EST 2017. Contains 282599 sequences.