A130569 Numbers of the form k*2^m + 1 for k odd, m >=1, that are not Proth numbers (A080075) (2^m <= k).

7, 11, 15, 19, 21, 23, 27, 29, 31, 35, 37, 39, 43, 45, 47, 51, 53, 55, 59, 61, 63, 67, 69, 71, 73, 75, 77, 79, 83, 85, 87, 89, 91, 93, 95, 99, 101, 103, 105, 107, 109, 111, 115, 117, 119, 121, 123, 125, 127, 131, 133, 135, 137, 139, 141, 143, 147, 149, 151, 153, 155

Offset

1,1

Links

Table of n, a(n) for n=1..61.

Example

a(1)=7 because 7 = 3*2^1 + 1 and 2^1 <= 3,
a(2)=11 because 11 = 5*2^1 + 1 and 2^1 <= 5,
a(3)=15 because 15 = 7*2^1 + 1 and 2^1 <= 7, ...

Maple

ts_neProth:=proc(n) local i, j, k, a, am; k := 2: am:= [ ]: for i from 1 to n do for j from 1 by 2 to n do a := j*k^(i)+1: if (k^(i) <= j) then am := [op(am), a ]: fi: od: od: RETURN( sort(am) ) end: ts_neProth(200);

Crossrefs

Sequence in context: A335652 A176852 A248630 * A294294 A078176 A097494

Adjacent sequences: A130566 A130567 A130568 * A130570 A130571 A130572

Keyword

nonn

Author

Jani Melik, Aug 10 2007

Status

approved