login
The OEIS is supported by the many generous donors to the OEIS Foundation.

 

Logo

Year-end appeal: Please make a donation to the OEIS Foundation to support ongoing development and maintenance of the OEIS. We are now in our 59th year, we have over 358,000 sequences, and we’ve crossed 10,300 citations (which often say “discovered thanks to the OEIS”).

Other ways to Give
Hints
(Greetings from The On-Line Encyclopedia of Integer Sequences!)
A073847 a(0) = 1, c(0) = 1, a(n) for n > 0 is the smallest prime a(n-1) + c(n), where c(n) is composite and larger than c(n-1). 0
1, 5, 11, 19, 29, 41, 59, 79, 101, 127, 157, 191, 227, 269, 313, 359, 409, 461, 521, 587, 659, 733, 809, 887, 967, 1049, 1151, 1259, 1373, 1489, 1607, 1733, 1861, 1993, 2129, 2267, 2411, 2557, 2707, 2861, 3019, 3181, 3347, 3517, 3691, 3877, 4073, 4271, 4481 (list; graph; refs; listen; history; text; internal format)
OFFSET

0,2

COMMENTS

Same as A070865 after first term. - David Wasserman, Jun 27 2005

LINKS

Table of n, a(n) for n=0..48.

EXAMPLE

a(6) = 59 since 59 = a(5) + c(6) = 41 + 18, 18 is composite and larger than c(5) = 12 and the composite numbers 14, 15, 16 do not lead to a prime when added to 41.

MATHEMATICA

a[n_] := a[n] = NextPrim[a[n - 1] + a[n - 1] - a[n - 2]]; a[0] = 1; a[1] = 5; Table[ a[n], {n, 0, 50}]

PROG

(PARI) {print1(a=1, ", "); c=1; for(n=1, 48, c++; while(isprime(c)||!isprime(a+c), c++); a=a+c; print1(a, ", "))}

CROSSREFS

Sequence in context: A110331 A028387 A106071 * A024833 A002327 A078179

Adjacent sequences: A073844 A073845 A073846 * A073848 A073849 A073850

KEYWORD

nonn

AUTHOR

Amarnath Murthy, Aug 14 2002

EXTENSIONS

Edited and extended by Klaus Brockhaus and Robert G. Wilson v, Aug 14 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 | Recents
The OEIS Community | Maintained by The OEIS Foundation Inc.

License Agreements, Terms of Use, Privacy Policy. .

Last modified December 5 06:35 EST 2022. Contains 358582 sequences. (Running on oeis4.)