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A336360
Numbers k for which bigomega(sigma(k)) >= bigomega(k), where bigomega (A001222) gives the number of prime factors with multiplicity, and sigma (A000203) gives the sum of divisors.
4
1, 2, 3, 5, 6, 7, 10, 11, 12, 13, 14, 15, 17, 19, 20, 21, 22, 23, 24, 26, 27, 28, 29, 30, 31, 33, 34, 35, 37, 38, 39, 40, 41, 42, 43, 44, 45, 46, 47, 49, 51, 52, 53, 54, 55, 56, 57, 58, 59, 60, 61, 62, 63, 65, 66, 67, 68, 69, 70, 71, 73, 74, 75, 76, 77, 78, 79, 82, 83, 84, 85, 86, 87, 88, 89, 90, 91, 92, 93, 94, 95, 97
OFFSET
1,2
COMMENTS
Numbers k such that A058063(k) >= A001222(k).
If terms x and y are present and gcd(x,y) = 1, then x*y is present also. This follows because both A001222 and A058063 are additive sequences, their difference A336386 is also.
PROG
(PARI) isA336360(n) = (bigomega(sigma(n))>=bigomega(n));
CROSSREFS
Cf. A000203, A001222, A058063, A336359 (complement).
Positions of nonnegative terms in A336386.
Sequence in context: A119316 A348964 A349026 * A102750 A375402 A349810
KEYWORD
nonn
AUTHOR
Antti Karttunen, Jul 20 2020
STATUS
approved