A187098 A permutation of the natural numbers related to Goldbach conjecture.

1, 2, 3, 4, 5, 6, 7, 9, 8, 11, 10, 13, 14, 12, 15, 17, 18, 16, 19, 21, 20, 23, 24, 25, 22, 27, 26, 29, 30, 28, 31, 33, 32, 35, 36, 39, 38, 42, 37, 34, 40, 43, 45, 41, 44, 48, 49, 46, 51, 47, 50, 53, 56, 57, 52, 55, 54, 60, 58, 63, 59, 65, 62, 66, 61, 70, 67, 69, 68, 71, 72, 73, 75, 74, 77, 78, 76, 81, 80, 84

Offset: 1

Author

Reinhard Zumkeller, Mar 04 2011

Keywords

• nonn

Comments

a(n) = if n <= 2 then n else A187085(n-2)/2;

for n > 2: a(n+1) = a(n) + (A187072(n) - A187072(n-2)) / 2.

Links

• Reinhard Zumkeller, Table of n, a(n) for n = 1..10000
• Index entries for sequences that are permutations of the natural numbers
• Index entries for sequences related to Goldbach conjecture

Crossrefs

Cf. A065306, A187099 (inverse).

Cf. A187085, A187072.

Programs

Haskell

a187098 n = a187098_list !! (n-1)
a187098_list = 1 : 2 : map (`div` 2) a187085_list