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A097620 Numbers having more prime factors than their neighbors together. 2
12, 16, 18, 24, 30, 32, 36, 40, 42, 48, 54, 60, 64, 72, 84, 88, 90, 96, 102, 108, 112, 120, 128, 132, 138, 140, 144, 150, 156, 160, 162, 168, 180, 192, 198, 200, 210, 216, 224, 228, 234, 240, 250, 252, 256, 264, 270, 272, 280, 282, 288, 294, 300, 304, 306, 308 (list; graph; refs; listen; history; text; internal format)
OFFSET
1,1
LINKS
FORMULA
{k: A001222(k) > A001222(k-1) + A001222(k+1)}. - Michael S. Branicky, Dec 16 2021
EXAMPLE
A001222(64) = A001222(2^6) = 6, A001222(64-1) = A001222(3*3*7) = 3, A001222(64+1) = A001222(5*13) = 2, and 6 > 3+2, therefore 64 is a term.
PROG
(Python)
from sympy import primeomega
def ok(n): return primeomega(n) > primeomega(n-1) + primeomega(n+1)
print([k for k in range(2, 309) if ok(k)]) # Michael S. Branicky, Dec 16 2021
CROSSREFS
Subsequence of A097619.
Cf. A001222.
Sequence in context: A107308 A051518 A043544 * A335222 A356863 A112548
KEYWORD
nonn
AUTHOR
Reinhard Zumkeller, Aug 17 2004
STATUS
approved

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Last modified March 29 03:39 EDT 2024. Contains 371264 sequences. (Running on oeis4.)