A110421 Integers with mutual residues -4.

5, 9, 41, 1841, 3396641, 11537183669441, 133106607022462246291930241, 17717368833032195779538884761310335951434822778039041

Offset

1,1

Comments

This is the special case k=4 of sequences with mutual residues -k. In general, a(1)=k+1 and a(n)=min{m | m>a(n-1), mod(m,a(i))=-k, i=1,...,n-1}.

An infinite coprime sequence

Links

Table of n, a(n) for n=1..8.

S. Mustonen, On integer sequences with mutual k-residues

Formula

a(1)=5, a(2)=9, a(n)=-1+a(1)*a(2)*...*a(n-1)

a(n)=a(n)^2+4*a(n)-4, n>3

Maple

a:=proc(k, n::nonnegint) option remember; if n<3 then RETURN(n*k+1); fi; if n=3 then RETURN(a(k, 1)*a(k, 2)-k); fi; a(k, n-1)*(a(k, n-1)+k)-k; end; seq(a(4, n), n=1..9);

Crossrefs

Sequence in context: A269702 A271016 A176967 * A176751 A123822 A226065

Adjacent sequences: A110418 A110419 A110420 * A110422 A110423 A110424

Keyword

nonn

Author

Seppo Mustonen, Sep 11 2005

Status

approved