A297894 Composite numbers that divide at least one Euclid number.

1843, 5263, 10147, 12629, 24047, 26869, 30031, 136109, 189001, 356189, 510511, 648077, 709493, 960359, 1293109, 1459817, 1513817, 1755431, 2263607, 2290129, 2578327, 2825041, 3173707, 3415703, 3440471, 4629071, 5007641, 5497781, 5698237, 6021971, 8614843

Offset: 1

Author

Jon E. Schoenfield, Jan 07 2018

Keywords

• nonn

Comments

The k-th Euclid number, A006862(k), is 1 plus the product of the first k primes, i.e., 1 + A002110(k). A113165 lists the numbers (> 1) that divide at least one Euclid number. It appears that the vast majority of terms in A113165 are prime; this sequence lists the composite numbers in A113165.

No composite less than 10^8 divides more than one Euclid number.

Examples

			a(1) = 1843 because 1843 = 19*97 is the smallest composite number that divides a Euclid number: 1843 divides 1 + A002110(7) = 1 + 2*3*5*7*11*13*17 = 510511 = 19*97*277. (Thus, 5263 (= 19*277), 26869 (= 97*277), and 19*97*277 = 510511 itself are also composites that divide a Euclid number; 5263 = a(2), 26869 = a(6), and 510511 = a(11).)
		

Crossrefs

Cf. A002110 (primorials), A006862 (Euclid numbers), A113165 (numbers > 1 that divide Euclid numbers), A297891 (numbers > 1 that divide exactly two Euclid numbers).