A060269 Distance of n-th primorial from closest prime.

1, 1, 1, 1, 19, 23, 37, 41, 1, 59, 1, 47, 67, 59, 61, 89, 89, 103, 79, 83, 89, 1, 103, 131, 113, 127, 223, 191, 163, 179, 389, 239, 151, 167, 173, 239, 199, 191, 199, 223, 233, 593, 293, 457, 227, 311, 373, 257

Offset

3,5

Links

Table of n, a(n) for n=3..50.

Example

7th primorial is surrounded by {510529,510481} primes in {19,71} distances of which the smaller is 19=a(7).

Maple

with(numtheory): [seq(min(nextprime(product(ithprime(j), j=1..n))-product(ithprime(j), j= >1..n), product(ithprime(j), j=1..n)-prevprime(product(ithprime(j), j=1..n >))), n=3..50)];

Mathematica

dnp[n_]:=Module[{a=NextPrime[n, -1], b=NextPrime[n]}, Min[n-a, b-n]]; dnp/@ FoldList[Times, Prime[Range[50]]] (* Harvey P. Dale, Jul 11 2017 *)

Crossrefs

Cf. A002110, A038710, A007014, A058044, A038711.

Sequence in context: A351121 A245585 A343741 * A245382 A075585 A052030

Adjacent sequences: A060266 A060267 A060268 * A060270 A060271 A060272

Keyword

nonn

Author

Labos Elemer, Mar 23 2001

Status

approved