|
Search: id:A109278
|
|
|
| A109278 |
|
Fastest increasing sequence: a(n) is a prime closest to the sum of all previous terms. |
|
+0
2
|
|
| 2, 2, 5, 11, 19, 41, 79, 157, 317, 631, 1259, 2521, 5039, 10079, 20161, 40343, 80669, 161333, 322669, 645329, 1290673, 2581349, 5162681, 10325369, 20650753, 41301493, 82602997, 165205981, 330411959, 660823921, 1321647869, 2643295709
(list; graph; listen)
|
|
|
OFFSET
|
1,1
|
|
|
COMMENT
|
Cf. A109277 slowest increasing sequence.
|
|
EXAMPLE
|
a(1)=2, sum(1)=2; prime closest to sum is 2, hence a(2)=2, sum(2)=4; there are two primes 3 and 5 closest to sum(2), we choose the largest one, hence a(3)=5, sum(3)=7, etc.
|
|
MATHEMATICA
|
s={2}; su=2; Do[If[PrimeQ[su], a=su, pp=PrimePi[su]; prv=Prime[pp]; nxt=Prime[pp+1]; a=If[su-prv<nxt-su, prv, nxt]]; AppendTo[s, a]; Print[a]; su+=a, {i, 42}]; s
|
|
CROSSREFS
|
Cf. A109277.
Sequence in context: A005637 A104080 A078405 this_sequence A112527 A049680 A058021
Adjacent sequences: A109275 A109276 A109277 this_sequence A109279 A109280 A109281
|
|
KEYWORD
|
nonn
|
|
AUTHOR
|
Zak Seidov (zakseidov(AT)yahoo.com), Jun 25 2005
|
|
|
Search completed in 0.002 seconds
|
