|
Search: id:A067747
|
|
|
| A067747 |
|
Primes interleaved between composite numbers: n-th prime followed by the n-th composite number. |
|
+0
2
|
|
| 2, 4, 3, 6, 5, 8, 7, 9, 11, 10, 13, 12, 17, 14, 19, 15, 23, 16, 29, 18, 31, 20, 37, 21, 41, 22, 43, 24, 47, 25, 53, 26, 59, 27, 61, 28, 67, 30, 71, 32, 73, 33, 79, 34, 83, 35, 89, 36, 97, 38, 101, 39, 103, 40, 107, 42, 109, 44, 113, 45, 127, 46, 131, 48, 137, 49, 139
(list; graph; listen)
|
|
|
OFFSET
|
1,1
|
|
|
LINKS
|
Zak Seidov, Table of n, a(n) for n = 1..1000.
|
|
MATHEMATICA
|
Array[c, 1000]; pc=-1; nc=0; Do[If[PrimeQ[n], If[pc==999, Break[], pc+=2; c[pc]=n], If[nc<=998, nc+=2; c[nc]=n, Goto[ne]]]; Label[ne], {n, 2, 20000}]; Table[c[i], {i, 1000}] - Zak Seidov (zakseidov(AT)yahoo.com), Mar 22 2008
Composite[n_Integer] := FixedPoint[n + PrimePi@ # + 1 &, n + PrimePi@ n + 1]; Table[{Prime@ n, Composite@ n}, {n, 35}] // Flatten (* Robert G. Wilson v, (rgwv(AT)rgwv.com), Jun 08 2008 *)
|
|
CROSSREFS
|
Cf. A073846.
Sequence in context: A135761 A086305 A073898 this_sequence A073846 A110458 A114112
Adjacent sequences: A067744 A067745 A067746 this_sequence A067748 A067749 A067750
|
|
KEYWORD
|
easy,nonn
|
|
AUTHOR
|
Amarnath Murthy (amarnath_murthy(AT)yahoo.com), Feb 26 2002
|
|
|
Search completed in 0.002 seconds
|
