Logo

Greetings from The On-Line Encyclopedia of Integer Sequences!

Hints

Search: id:A114234
Displaying 1-1 of 1 results found. page 1
     Format: long | short | internal | text      Sort: relevance | references | number      Highlight: on | off
A114234 n(k) is the minimum n that requires at least k to make 2*Prime[n]+Prime[k] a prime. +0
4
3, 11, 5, 47, 17, 106, 64, 157, 133, 26, 236, 308, 72, 496, 122, 207, 152, 142, 197, 259, 514, 497, 1266, 1482, 2005, 2193, 1380, 964, 3662, 534, 4055, 667, 2513, 6083, 1794, 689, 3332, 5771, 3713, 4587, 3450, 12520, 5712, 3242, 10252, 18663, 11912, 25124 (list; graph; listen)
OFFSET

2,1

COMMENT

Shows the first 204 items; The first appearance in A114233; Sequence is defined for all k>=2.

EXAMPLE

k=2: 2*Prime[3]+Prime[2]=13 is prime, so n(2)=3;

2*Prime[4]+Prime[2]=17

2*Prime[5]+Prime[2]=25, ... 2*Prime[5]+Prime[4]=29 ==> n(4)=5;

MATHEMATICA

Do[n[k] = 0, {k, 2, 2000}]; ct = 0; nm = 0; n2 = 0; n1 = 3; p1 = 5; While[ct < 200, n2 = 1; p2 = Prime[n2]; While[cp = 2*p1 + p2; ! PrimeQ[cp], n2++; p2 = Prime[n2]]; If[n[n2] == 0, n[ n2] = n1; If[n2 > nm, nm = n2]; If[n2 <= 201, ct++ ]; Print[Table[n[k], {k, 2, nm}]]]; n1++; p1 = Prime[n1]];

CROSSREFS

Cf. A073703, A114227, A114229, A114232, A114233.

Sequence in context: A134969 A139686 A130537 this_sequence A120299 A094900 A164808

Adjacent sequences: A114231 A114232 A114233 this_sequence A114235 A114236 A114237

KEYWORD

nonn

AUTHOR

Lei Zhou (lzhou5(AT)emory.edu), Nov 20 2005

page 1

Search completed in 0.005 seconds

Lookup | Welcome | Find friends | Music | Plot 2 | Demos | Index | Browse | More | WebCam
Contribute new seq. or comment | Format | Transforms | Puzzles | Hot | Classics
More pages | Superseeker | Maintained by N. J. A. Sloane (njas@research.att.com)

Last modified November 29 12:46 EST 2009. Contains 167659 sequences.


AT&T Labs Research