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A209876 a(n) = 36*n - 6. 0

%I #13 Jun 18 2021 19:54:35

%S 30,66,102,138,174,210,246,282,318,354,390,426,462,498,534,570,606,

%T 642,678,714,750,786,822,858,894,930,966,1002,1038,1074,1110,1146,

%U 1182,1218,1254,1290,1326,1362,1398,1434,1470,1506,1542,1578,1614,1650,1686,1722,1758,1794,1830,1866,1902,1938,1974

%N a(n) = 36*n - 6.

%C It appears that the sum of divisors of each term is a multiple of 36. For example, the divisors of a(3)=102 are {1, 2, 3, 6, 17, 34, 51, 102}, with sum 216=6*36.

%C It also appears that the sum of divisors of each term of {K*n-6} is a multiple of K for K = 72, 144, and 288.

%H <a href="/index/Rec#order_02">Index entries for linear recurrences with constant coefficients</a>, signature (2,-1).

%F G.f.: (6x+30)/(x-1)^2 - _Harvey P. Dale_, Jun 18 2021

%t 36*Range[60]-6 (* or *) LinearRecurrence[{2,-1},{30,66},60] (* _Harvey P. Dale_, Jun 18 2021 *)

%Y Cf. A183010.

%K nonn

%O 1,1

%A _John W. Layman_, Mar 14 2012

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Last modified April 19 21:09 EDT 2024. Contains 371798 sequences. (Running on oeis4.)