A376154 Numbers that are not the sum of the nonprime divisors of k for any k.

0, 2, 3, 4, 6, 8, 9, 12, 14, 17, 18, 19, 20, 21, 24, 25, 28, 30, 31, 32, 33, 38, 41, 42, 43, 44, 45, 46, 48, 49, 51, 53, 54, 57, 60, 64, 65, 67, 68, 69, 72, 73, 74, 76, 77, 79, 80, 81, 82, 85, 89, 90, 91, 93, 97, 98, 99, 100, 101, 102, 103, 104, 105, 106, 108, 109, 110, 113, 114, 117, 121, 126

Offset: 1

Author

Robert Israel, Sep 12 2024

Keywords

• nonn

Comments

Nonnegative numbers that do not appear in A023890.

If k > 1 and k = A023890(m), then m must be composite with m < k. Thus k is a term of this sequence if k does not appear in A023890(1..k-1).

Examples

			a(6) = 8 is a term because 8 is not A023890(1) = 1 or A023890(4) = 5 or A023890(6) = 7.
		

Links

• Robert Israel, Table of n, a(n) for n = 1..10000

Crossrefs

Cf. A023890.

Programs

Maple

N:= 100: # to get terms <= N
f:= proc(n) convert(remove(isprime, numtheory:-divisors(n)),`+`) end proc:
S:= {$0..N} minus map(f, {$1..N-1}):
sort(convert(S,list));