A350098
a(n) is the lower end of a record gap A349995(n) between consecutive odd squarefree semiprimes (A046388).
Original entry on oeis.org
15, 21, 95, 267, 2369, 6559, 8817, 13705, 15261, 21583, 35981, 66921, 113009, 340891, 783757, 872219, 3058853, 3586843, 5835191, 12345473, 108994623, 248706917, 268749691, 679956119, 709239621, 3648864859, 3790337723, 4171420481, 33955869693, 34279038379, 34840796369
Offset: 1
Starting at a(3)=95 the terms coincide with the known terms of
A114057.
A350099
a(n) is the upper end of a record gap A349995(n) between consecutive odd squarefree semiprimes (A046388).
Original entry on oeis.org
21, 33, 111, 287, 2391, 6583, 8843, 13733, 15293, 21619, 36019, 66961, 113053, 340941, 783809, 872279, 3058917, 3586913, 5835265, 12345557, 108994713, 248707009, 268749791, 679956221, 709239737, 3648864977, 3790337843, 4171420613, 33955869829, 34279038517, 34840796509
Offset: 1
A114057
Start of record gap in odd semiprimes A046315.
Original entry on oeis.org
9, 25, 39, 95, 267, 2369, 6559, 8817, 13705, 15261, 21583, 35981, 66921, 113009, 340891, 783757, 872219, 3058853, 3586843, 5835191, 12345473, 108994623, 248706917, 268749691, 679956119, 709239621, 3648864859, 3790337723, 4171420481, 33955869693, 34279038379
Offset: 1
a(1) = A046315(2)-A046315(1) = 15 - 9 = 6.
a(2) = A046315(5)-A046315(4) = 33 - 25 = 8.
a(3) = A046315(8)-A046315(7) = 49 - 39 = 10.
a(4) = A046315(20)-A046315(19) = 111 - 95 = 16.
a(5) = A046315(55)-A046315(54) = 287 - 267 = 20.
Starting at a(4)=95 the known terms of this sequence coincide with
A350098.
-
f[n_] := Block[{k = n + 2}, While[ Plus @@ Last /@ FactorInteger@k != 2, k += 2]; k]; lst = {}; d = 0; a = b = 9; Do[{a, b} = {b, f[a]}; If[b - a > d, d = b - a; AppendTo[lst, a]], {n, 10^8}]; lst (* Robert G. Wilson v, Feb 03 2006 *)
A350096
a(n) is the larger of 2 consecutive primes bounding an interval containing a record number A350097(n) of odd squarefree semiprimes (A046388).
Original entry on oeis.org
17, 37, 97, 211, 223, 907, 1151, 1361, 10007, 15727, 19661, 44351, 156007, 370373, 396833, 492227, 1357333, 1671907, 3826157, 17836561, 20831533, 47465443, 107534789, 122164969, 434865671, 436273291, 2300942869, 4302407713, 10726905041, 25056082543, 42652618807
Offset: 1
A350097 gives the corresponding counts.
Showing 1-4 of 4 results.
Comments