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A356744 Numbers k such that both k and k+2 have exactly 8 divisors. 4

%I #8 Aug 25 2022 09:13:22

%S 40,54,102,128,136,152,182,184,230,246,248,374,424,470,472,534,582,

%T 663,710,806,822,824,854,872,902,904,999,1105,1192,1256,1309,1334,

%U 1336,1432,1446,1526,1542,1545,1576,1593,1645,1686,1784,1832,1864,1885,1910,1928,2006,2013

%N Numbers k such that both k and k+2 have exactly 8 divisors.

%H Jianing Song, <a href="/A356744/b356744.txt">Table of n, a(n) for n = 1..10000</a>

%e 54 is a term since 54 and 56 both have 8 divisors.

%o (PARI) isA356744(n) = numdiv(n)==8 && numdiv(n+2)==8

%Y Numbers k such that k and k+2 both have exactly m divisors: A001359 (m=2), A356742 (m=4), A356744 (m=6), this sequence (m=8).

%Y Cf. also A274357 (numbers k such that k and k+1 both have exactly 8 divisors).

%K nonn

%O 1,1

%A _Jianing Song_, Aug 25 2022

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Last modified August 16 18:55 EDT 2024. Contains 375177 sequences. (Running on oeis4.)