A212665 Numbers such that the greatest prime divisor is less than the sum of the other distinct prime divisors.

105, 210, 315, 385, 420, 429, 462, 525, 630, 715, 735, 770, 840, 858, 910, 924, 945, 969, 1001, 1050, 1105, 1155, 1260, 1287, 1309, 1326, 1365, 1386, 1430, 1470, 1540, 1547, 1575, 1615, 1680, 1716, 1729, 1820, 1848, 1870, 1890, 1925, 1938, 2002, 2100, 2145

Offset

1,1

Links

Amiram Eldar, Table of n, a(n) for n = 1..10000

Example

105 is in the sequence because 105 = 3*5*7 and 7 < 5 + 3 = 8.

Maple

with(numtheory):for n from 2 to 3000 do:x:=factorset(n):m:=nops(x):s:=0: s:=sum( '
x[i] ', 'i'=1..m):q:=s-x[m]:if x[m] < q then printf(`%d, `, n):else fi:od:

Mathematica

aQ[n_] := Max[(p = FactorInteger[n][[;; , 1]])] < Total @ Most @ p; Select[Range[2200], aQ] (* Amiram Eldar, Sep 08 2019 *)

Crossrefs

Sequence in context: A273521 A214082 A069692 * A242063 A228307 A179143

Adjacent sequences: A212662 A212663 A212664 * A212666 A212667 A212668

Keyword

nonn

Author

Michel Lagneau, May 23 2012

Status

approved