A354740 Indices of records in A218344.

1, 3, 14, 15, 25, 38, 61, 121, 288, 1427, 3201, 3532, 4514, 18824, 56506, 138299, 160019, 175672, 389021, 792425, 1307363, 2484543, 5810361, 6570899, 18661982, 28689761, 54425951, 120552563, 145950769, 1046047048, 11369776859, 12564976008, 19468787723, 36754001297

Offset

1,2

Comments

The corresponding composite numbers A002808(a(n)) are 4, 8, 24, 25, 38, 55, 85, ... (see the link for more values).

Links

Table of n, a(n) for n=1..34.

Amiram Eldar, Table of n, a(n), A218345(n), A002808(a(n)) for n = 1..34

Formula

A218344(a(n)) = A218345(n).

Mathematica

comp = Select[Range[10^6], CompositeQ]; f[n_] := Module[{k = 1}, While[! PrimeQ[k*n + 1], k++]; k]; vs = f /@ comp; m = 0; s = {}; Do[v = vs[[k]]; If[v > m, m = v; AppendTo[s, k]], {k, 1, Length[vs]}]; s

Crossrefs

Cf. A002808, A218344, A218345.

Sequence in context: A070418 A178363 A294997 * A034120 A303222 A037244

Adjacent sequences: A354737 A354738 A354739 * A354741 A354742 A354743

Keyword

nonn

Author

Amiram Eldar, Jun 05 2022

Status

approved