A039739 - OEIS

A039739

a(n)=2*q-prime(n), where q is the prime < p(n) for which (prime(n) mod q) is maximal.

1, 1, 3, 3, 1, 5, 3, 3, 5, 3, 1, 5, 3, 11, 5, 3, 1, 7, 3, 1, 3, 3, 5, 9, 5, 3, 11, 9, 5, 7, 3, 5, 3, 9, 7, 1, 3, 11, 5, 15, 13, 3, 1, 5, 3, 3, 3, 27, 25, 21, 15, 13, 3, 5, 11, 5, 3, 1, 17, 15, 5, 7, 3, 1, 9, 3, 9, 11, 9, 5, 3, 15, 9, 3, 3, 5, 1, 21, 13, 3, 1

(list; graph; refs; listen; history; text; internal format)

OFFSET

2,3

LINKS

Table of n, a(n) for n=2..82.

FORMULA

a(n) = 2*A039734(n)-prime(n). - R. J. Mathar, May 03 2021

MAPLE

A039739 := proc(n)

local p, maxmod, q, qpiv ;

p := ithprime(n) ;

for j from 1 to n-1 do

q := ithprime(j) ;

if j = 1 then

qpiv := q ;

maxmod := modp(p, q) ;

else

if modp(p, q) > maxmod then

maxmod := modp(p, q) ;

qpiv := q ;

end if;

end do:

2*qpiv-p ;

end proc:

seq(A039739(n), n=2..80) ; # R. J. Mathar, May 03 2021

CROSSREFS

Sequence in context: A316366 A111945 A002143 * A160496 A105663 A318319

Adjacent sequences: A039736 A039737 A039738 * A039740 A039741 A039742

KEYWORD

nonn

AUTHOR

Clark Kimberling

STATUS

approved