A122985 Smallest composite number greater than n, relatively prime to n, such that a(n)-n is also composite.

9, 27, 25, 25, 9, 55, 15, 33, 25, 49, 15, 77, 21, 39, 49, 25, 21, 95, 25, 69, 25, 49, 27, 49, 33, 35, 35, 55, 33, 121, 35, 57, 49, 49, 39, 85, 45, 63, 49, 49, 45, 185, 49, 65, 49, 55, 51, 125, 55, 77, 55, 77, 57, 119, 63, 65, 65, 85, 63, 203, 65, 77, 85, 85, 69, 91, 75, 77, 77

Offset

1,1

Links

Table of n, a(n) for n=1..69.

Mathematica

scn[n_]:=Module[{k=n+1}, While[!CompositeQ[k]||!CoprimeQ[n, k] || !CompositeQ[ k-n], k++]; k]; Array[scn, 70] (* Harvey P. Dale, Jul 26 2019 *)

Crossrefs

Equals A122984(n) + n. Cf. A096076.

Sequence in context: A010817 A374074 A205973 * A255622 A209511 A370872

Adjacent sequences: A122982 A122983 A122984 * A122986 A122987 A122988

Keyword

easy,nonn

Author

Franklin T. Adams-Watters, Sep 22 2006

Status

approved