A082453 a(n)=2n+1 where n is such that A083344(n) is zero.

3, 5, 7, 9, 11, 13, 15, 17, 19, 21, 23, 25, 27, 29, 31, 33, 35, 37, 39, 41, 43, 47, 49, 51, 53, 55, 57, 59, 61, 63, 65, 67, 69, 71, 73, 77, 79, 81, 83, 85, 87, 89, 91, 93, 95, 97, 99, 101, 103, 105, 107, 109, 111, 113, 115, 119, 121, 123, 125, 127, 129, 131, 133, 135, 137

Offset

1,1

Links

Table of n, a(n) for n=1..65.

Example

First two missing odd numbers are 45 and 75; missing terms are in A082452.

Mathematica

di[x_] := Apply[LCM, Divisors[x]+1] (*A066715=*)t1=Table[GCD[2*n+1, DivisorSigma[1, 2*n+1]], {n, 1, 2048}]; (*A082457=*)t2=Table[GCD[2*w+1, di[1+2*w]], {w, 1, 2048}]; (*A083344=*)t3=t2-t1; (*A082453=*)1+2*Flatten[Position[Abs[Sign[t3]], 0]];

Crossrefs

Cf. A057643, A066715, A000203, A082457, A083344.

Sequence in context: A105356 A326835 A294748 * A033041 A077797 A353076

Adjacent sequences: A082450 A082451 A082452 * A082454 A082455 A082456

Keyword

nonn

Author

Labos Elemer, Apr 25 2003

Status

approved