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A354740
Indices of records in A218344.
2
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).
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
KEYWORD
nonn
AUTHOR
Amiram Eldar, Jun 05 2022
STATUS
approved