A074846 a(n) is the smallest k > n such that n*k+1 is prime.

2, 3, 4, 7, 6, 7, 10, 9, 12, 13, 18, 13, 24, 15, 16, 21, 18, 21, 22, 2, 22, 28, 26, 25, 28, 33, 28, 34, 32, 33, 36, 36, 34, 37, 42, 43, 40, 39, 48, 43, 42, 46, 46, 47, 48, 51, 50, 54, 52, 51, 56, 55, 56, 55, 58, 60, 58, 61, 60, 67, 66, 63, 66, 67, 68, 67, 70, 75, 70, 79, 72, 79

Offset

1,1

Links

Table of n, a(n) for n=1..72.

Example

a(1)=2 because 1*2+1=3 is the smallest prime of the form 1*k+1 with k > 1.
a(4)=7 because 4*7+1=29 is the smallest prime of the form 4*k+1 with k > 4.
a(100)=103 because 100*103+1=10301 is the smallest prime of the form 100*k+1 with k > 100.

Crossrefs

Sequence in context: A265363 A319651 A340632 * A120225 A247798 A130685

Adjacent sequences: A074843 A074844 A074845 * A074847 A074848 A074849

Keyword

nonn

Author

Zak Seidov, Sep 10 2002

Status

approved