Voozh

A335579

a(n) is the sum of all numbers that divide at least one of the composites between prime(n) and prime(n+1).

7, 12, 42, 28, 75, 39, 106, 214, 72, 289, 202, 96, 230, 429, 471, 168, 544, 362, 195, 631, 429, 749, 1125, 540, 216, 560, 280, 612, 2557, 679, 1195, 288, 2169, 372, 1391, 1378, 830, 1540, 1479, 546, 2750, 508, 1025, 468, 3835, 3900, 1245, 560, 1262, 1995, 744, 3576, 2328, 2195, 2345, 720, 2449

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

OFFSET

2,1

LINKS

Robert Israel, Table of n, a(n) for n = 2..10000

EXAMPLE

For n=4, the composites between prime(4) and prime(5) are 8, 9, 10.

The numbers that divide at least one of these are {1,2,4,8} union {1,3,9} union {1,2,5,10} = {1,2,3,4,5,8,9,10}, and a(4) = 1+2+3+4+5+8+9+10 = 42.

MAPLE

f:= proc(n) local i, S;

S:= `union`(seq(numtheory:-divisors(i), i=ithprime(n)+1..ithprime(n+1)-1));

convert(S, `+`);