A343137 Positions of records in A188172.
1, 7, 63, 315, 945, 1575, 3465, 10395, 17325, 26775, 45045, 135135, 225225, 405405, 675675, 1576575, 2027025, 2297295, 3828825, 6891885, 11486475, 26801775, 34459425, 43648605, 72747675, 130945815, 218243025, 509233725, 654729075, 1003917915, 1527701175, 3011753745, 4583103525
Offset: 1
Keywords
Examples
945 is in the sequence as A188172(945) = 4 via the divisors 7, 15, 63 and 135 and no positive integer < 945 has at least four such (7 (mod 8)) divisors.
Programs
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Mathematica
Function[{s, r}, Map[FirstPosition[s, #][[1]] &, r]] @@ {#, Union@ FoldList[Max, #]} &@ Array[DivisorSum[#, 1 &, Mod[#, 8] == 7 &] &, 10^6] (* Michael De Vlieger, Apr 08 2021 *)