A343185 Numbers k such that 2*k is a multiple of A045917(k).

2, 3, 4, 5, 6, 7, 8, 9, 10, 12, 14, 15, 16, 18, 19, 30, 33, 34, 35, 36, 40, 44, 45, 46, 56, 60, 70, 76, 80, 92, 100, 112, 114, 128, 130, 140, 145, 148, 182, 184, 209, 210, 221, 228, 238, 247, 270, 276, 286, 297, 324, 344, 372, 399, 408, 410, 425, 429, 437, 444, 460, 468, 475, 504, 506, 507, 510

Offset

1,1

Links

Robert Israel, Table of n, a(n) for n = 1..600

Example

a(4) = 5 is a term because 2*5 = 10 is a multiple of A045917(5) = 2.

Maple

P:= select(isprime, [2, seq(i, i=3..2000, 2)]):
filter:= proc(n) local k1, k2;
   k1:= ListTools:-BinaryPlace(P, n+1);
   k2:= ListTools:-BinaryPlace(P, 2*n+1);
   2*n mod nops(convert(P[1..k1], set) intersect map(t -> 2*n-t, convert(P[k1..k2], set))) = 0
end proc:
select(filter, [$2..1000]);

Crossrefs

Cf. A045917.

Sequence in context: A243463 A247805 A164713 * A070331 A080672 A056757

Adjacent sequences: A343182 A343183 A343184 * A343186 A343187 A343188

Keyword

nonn

Author

J. M. Bergot and Robert Israel, Apr 18 2021

Status

approved