

A141766


A positive integer n is included if both (p1) and (p+1) divide n for every prime p that divides n.


4



1, 12, 24, 36, 48, 60, 72, 96, 108, 120, 144, 168, 180, 192, 216, 240, 288, 300, 324, 336, 360, 384, 432, 480, 504, 540, 576, 600, 648, 660, 672, 720, 768, 840, 864, 900, 960, 972, 1008, 1080, 1152, 1176, 1200, 1296, 1320, 1344, 1440, 1500, 1512, 1536, 1620
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OFFSET

1,2


COMMENTS

Every term is a multiple of 12.


LINKS



EXAMPLE

120 has the prime factorization of 2^3 * 3^1 * 5^1. The distinct primes dividing 120 are therefore 2,3,5. 21=1, 31=2 and 51=4 all divide 120. Also, 2+1=3, 3+1=4 and 5+1=6 all divide 120. So 120 is included in the sequence.


MATHEMATICA

Select[Range[2, 1620], Function[n, AllTrue[FactorInteger[n][[All, 1]], AllTrue[# + {1, 1}, Divisible[n, #] &] &]]] (* Michael De Vlieger, Sep 22 2017 *)


PROG

(Haskell)
a141766 n = a141766_list !! (n1)
a141766_list = filter f [1..] where
f x = all (== 0) $ map (mod x) $ (map pred ps) ++ (map succ ps)
where ps = a027748_row x


CROSSREFS



KEYWORD

nonn


AUTHOR



EXTENSIONS



STATUS

approved



