A345668 Last prime minus distance to last prime.

1, 2, 1, 4, 3, 6, 5, 4, 3, 10, 9, 12, 11, 10, 9, 16, 15, 18, 17, 16, 15, 22, 21, 20, 19, 18, 17, 28, 27, 30, 29, 28, 27, 26, 25, 36, 35, 34, 33, 40, 39, 42, 41, 40, 39, 46, 45, 44, 43, 42, 41, 52, 51, 50, 49, 48, 47, 58, 57, 60, 59, 58, 57, 56, 55, 66, 65, 64

Offset

3,2

Links

Table of n, a(n) for n=3..70.

Formula

a(n) = p - (n-p) = 2*p - n where p is the largest prime < n.

a(n) = A151799(n) - A049711(n).

a(n) = A175856(n-1) - 1.

Mathematica

a[n_] := 2 * NextPrime[n, -1] - n; Array[a, 100, 3] (* Amiram Eldar, Jun 21 2021 *)

Crossrefs

Cf. A049711, A151799, A175856.

Sequence in context: A351752 A361189 A004560 * A076981 A355678 A355679

Adjacent sequences: A345665 A345666 A345667 * A345669 A345670 A345671

Keyword

nonn

Author

Brian Beard, Jun 21 2021

Extensions

More terms from Jon E. Schoenfield, Jun 21 2021

Status

approved