login

Year-end appeal: Please make a donation to the OEIS Foundation to support ongoing development and maintenance of the OEIS. We are now in our 61st year, we have over 378,000 sequences, and we’ve reached 11,000 citations (which often say “discovered thanks to the OEIS”).

A101549
Composite lopsided numbers: composite numbers n such that the largest prime factor > 2 sqrt(n).
2
22, 26, 34, 38, 39, 46, 51, 57, 58, 62, 68, 69, 74, 76, 82, 86, 87, 92, 93, 94, 106, 111, 115, 116, 118, 122, 123, 124, 129, 134, 141, 142, 145, 146, 148, 155, 158, 159, 164, 166, 172, 174, 177, 178, 183, 185, 186, 188, 194, 201, 202, 203, 205, 206, 212, 213
OFFSET
1,1
COMMENTS
All primes > 3 are also lopsided. See A101550 for all lopsided numbers.
LINKS
G. Everest, S. Stevens, D. Tamsett and T. Ward, Primitive Divisors of Quadratic Polynomial Sequences
MATHEMATICA
Select[Range[2, 300], !PrimeQ[ # ]&&FactorInteger[ # ][[ -1, 1]]>2Sqrt[ # ]&]
CROSSREFS
Cf. A063763 (composite n such that the largest prime factor > sqrt(n)), A064052 (n such that the largest prime factor > sqrt(n)).
Sequence in context: A162422 A063940 A046442 * A277624 A243140 A321996
KEYWORD
nonn
AUTHOR
T. D. Noe, Dec 06 2004
STATUS
approved