A090095 a(n) is the smallest composite number coprime to n, n+1, n+2, n+3, n+4 and n+5.

49, 121, 121, 121, 121, 169, 169, 49, 289, 289, 289, 121, 121, 121, 49, 121, 169, 169, 169, 169, 289, 49, 121, 121, 121, 121, 121, 169, 49, 169, 169, 169, 169, 121, 121, 49, 121, 121, 289, 169, 169, 169, 49, 169, 121, 121, 121, 121, 121, 49, 361, 289, 169, 169

Offset

1,1

Links

Harvey P. Dale, Table of n, a(n) for n = 1..1000

Formula

a(n) = A053674(n)^2.

Mathematica

m=0; Table[fla=1; Do[s=GCD[n, k]; s1=GCD[n, k+1]; s2=GCD[n, k+2]; s3=GCD[n, k+3]; s4=GCD[n, k+4]; s5=GCD[n, k+5]; If[Equal[s, 1]&&Equal[s1, 1]&&Equal[s2, 1]&&Equal[s3, 1]&& Equal[s4, 1]&&Equal[s5, 1]&&!PrimeQ[n]&&!Equal[n, 1]&&Equal[fla, 1], m=m+1; Print[n]; fla=0], {n, 1, 1000}], {k, 1, 256}]
scn[n_]:=Module[{k=4, c=n+Range[0, 5]}, While[PrimeQ[k]||!AllTrue[c, CoprimeQ[ k, #]&], k++]; k]; Array[scn, 60] (* Requires Mathematica version 10 or later *) (* Harvey P. Dale, Jul 30 2020 *)

Crossrefs

Cf. A053669, A053670, A053671, A053672, A053673, A053674.

Cf. A090092, A090093, A090094.

Sequence in context: A044617 A216169 A348054 * A163245 A084733 A338499

Adjacent sequences: A090092 A090093 A090094 * A090096 A090097 A090098

Keyword

nonn

Author

Labos Elemer, Nov 26 2003

Status

approved