|
Search: id:A014687
|
|
|
| A014687 |
|
In sequence of odd primes add 1 to first prime, 3rd prime, 5th prime, ... then subtract 1 from 2nd prime, fourth prime, sixth prime and so on. |
|
+0
9
|
|
| 4, 4, 8, 10, 14, 16, 20, 22, 30, 30, 38, 40, 44, 46, 54, 58, 62, 66, 72, 72, 80, 82, 90, 96, 102, 102, 108, 108, 114, 126, 132, 136, 140, 148, 152, 156, 164, 166, 174, 178, 182, 190, 194, 196, 200, 210, 224, 226, 230, 232, 240, 240, 252, 256, 264, 268, 272, 276
(list; graph; listen)
|
|
|
OFFSET
|
1,1
|
|
|
FORMULA
|
a(n)+a(n-1) = prime(n)+prime(n+1) i.e. a(n) = prime(n)+prime(n+1)-a(n-1) generates sequence with initial value a(1)=4. - Labos E. (labos(AT)ana.sote.hu), Apr 24 2003; corrected by Dean Hickerson (dean(AT)math.ucdavis.edu), Apr 27 2003
|
|
EXAMPLE
|
a(4)+a(3) = 10+8 = 18 = p(4)+p(5) = 7+11
|
|
MATHEMATICA
|
a[1]=4; a[n_] := a[n]=Prime[n]+Prime[n+1]-a[n-1]
|
|
CROSSREFS
|
Sequence in context: A101921 A093340 A046558 this_sequence A004024 A086663 A003829
Adjacent sequences: A014684 A014685 A014686 this_sequence A014688 A014689 A014690
|
|
KEYWORD
|
nonn,easy
|
|
AUTHOR
|
Mohammad K. Azarian (ma3(AT)evansville.edu)
|
|
EXTENSIONS
|
More terms from Erich Friedman (erich.friedman(AT)stetson.edu).
|
|
|
Search completed in 0.002 seconds
|
