A073170 a(1) = a(2) = 0; for n>2, a(n) = prime(n-1)-n+1.

0, 0, 1, 2, 3, 6, 7, 10, 11, 14, 19, 20, 25, 28, 29, 32, 37, 42, 43, 48, 51, 52, 57, 60, 65, 72, 75, 76, 79, 80, 83, 96, 99, 104, 105, 114, 115, 120, 125, 128, 133, 138, 139, 148, 149, 152, 153, 164, 175, 178, 179, 182, 187, 188, 197, 202, 207, 212, 213, 218, 221

Offset

1,4

Comments

Smallest x such that A002808(x)-x (cf. A073169) equals n, or 0 if no such value exists.

Links

Table of n, a(n) for n=1..61.

Formula

a(n)=Min{x; composite[x]-x=n}

Mathematica

f[x_] := FixedPoint[x+PrimePi[ # ]+1&, x] t=Table[0, {100}]; Do[s=f[n]-n; If[s<101&&t[[s]]==0, t[[s]]=n], {n, 1, 10000}]; t
Join[{0, 0}, Table[Prime[n-1]-n+1, {n, 3, 70}]] (* Harvey P. Dale, Dec 18 2012 *)

Crossrefs

Cf. A002808, A073168, A073169. Essentially same sequence as A014689.

Cf. A000040, A014689.

Sequence in context: A190670 A226115 A359503 * A014689 A117206 A026443

Adjacent sequences: A073167 A073168 A073169 * A073171 A073172 A073173

Keyword

nonn

Author

Labos Elemer, Jul 19 2002

Extensions

Simpler description from Vladeta Jovovic, Mar 29 2003

Definition corrected by Harvey P. Dale, Dec 18 2012

Status

approved