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

1,2

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).

Links

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

Example

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

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));

Crossrefs

Cf. A023890.

Sequence in context: A116621 A036407 A374243 * A145807 A278962 A122380

Adjacent sequences: A376151 A376152 A376153 * A376155 A376156 A376157

Keyword

nonn

Author

Robert Israel, Sep 12 2024

Status

approved