cp's OEIS Frontend

This is a front-end for the Online Encyclopedia of Integer Sequences, made by Christian Perfect. The idea is to provide OEIS entries in non-ancient HTML, and then to think about how they're presented visually. The source code is on GitHub.

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

Original entry on oeis.org

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

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Author

Jani Melik, Aug 10 2007

Keywords

Examples

			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, ...
		

Programs

  • 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);