|
| |
|
|
A070284
|
|
Smallest of 4 consecutive numbers each divisible by a square.
|
|
5
| |
|
|
242, 844, 845, 1680, 1681, 2888, 2889, 3174, 3624, 3625, 3750, 5046, 5047, 8475, 8523, 8954, 10050, 10827, 10924, 10925, 11322, 13374, 14748, 14749, 15775, 15848, 15849, 16575, 17404, 17405, 19647, 19940, 19941, 20574, 21462
(list; graph; refs; listen; history; internal format)
|
|
|
|
OFFSET
| 1,1
|
|
|
COMMENTS
| This sequence has positive density in N; the density is around 0.002.
The sequence includes an infinite family of arithmetic progressions. Such AP's can be constructed to each term, with large differences [like e.g. square of primorials, A061742]. It is necessary to solve suitable systems of linear Diophantine equations. E.g.: subsequences of quadruples of terms = {44100k+29349, 44100k+29350, 44100k+29351, 44100+29352} = {9(49000k+3261, 25(1764k+1174), 49(900k+599), 4(11025k+7338)}; starting terms in this sequence = {29349, 73449, 117649...}; difference = A002110(4)^2 = 2310^2. - Labos E. (labos(AT)ana.sote.hu), Nov 25 2002
|
|
|
LINKS
| Charles R Greathouse IV, Table of n, a(n) for n = 1..10000
|
|
|
MATHEMATICA
| f[n_] := Union[Transpose[FactorInteger[n]][[2]]][[ -1]]; a = 0; b = 1; c = 0; Do[d = f[n]; If[a > 1 && b > 1 && c > 1 && d > 1, Print[n - 3]]; a = b; b = c; c = d, {n, 4, 10^6}]
|
|
|
CROSSREFS
| Cf. A070258, A068781, A045882, A049535, A077647, A078143.
Sequence in context: A184023 A094908 A205594 * A160551 A165935 A006601
Adjacent sequences: A070281 A070282 A070283 * A070285 A070286 A070287
|
|
|
KEYWORD
| nonn
|
|
|
AUTHOR
| Sharon Sela (sharonsela(AT)hotmail.com), May 09 2002
|
|
|
EXTENSIONS
| More terms from Robert G. Wilson v (rgwv(AT)rgwv.com), May 09 2002
b-file from Charles R Greathouse IV (charles.greathouse(AT)case.edu), Jul 23 2010
|
| |
|
|
