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A277875 a(n) is the odd multiplier q in the expressions 2*(q*2^n - 1) and 2*(q*3^n - 1) of numbers A277215(n) and A277874(n), respectively. 2

%I #7 Nov 04 2016 04:54:49

%S 1,7,1,1,1,19,13,1,1,1,1,7,5,11,1,1,1,7,11,1,1,1,1,1,1,7,5,1,1,7,1,1,

%T 1,1,1,11,5,1,1,1,1,1,1,1,1,7,5,1,1,7,1,1,1,7,1,1,1,7,5,11,1,7,5,1,1,

%U 7,1,1,1,11,1,1,1,1,1,11,1,7,1,1,1,1,1,11,1,1,1,1,1,1,1,1,1,7,1,1,1,1,1,1

%N a(n) is the odd multiplier q in the expressions 2*(q*2^n - 1) and 2*(q*3^n - 1) of numbers A277215(n) and A277874(n), respectively.

%C The position numbers for odd numbers 5, 7, 11, 13 and 19 for the first 200 numbers in the sequence are listed in the Comments section of A277215.

%e a(0) = 1 since 0 = 2*(1*2^0 - 1) is the start and end of the first alternating sequence of 1 element and the maximum of its trajectory.

%e a(5) = 19 since 9232 = 2*(19*3^5 - 1) is the last element in the first alternating sequence of 11 elements - 1214, 607, 1822, 911, 2734, 1367, 4102, 2051, 6154, 3077, 9232 - that ends in the trajectory maximum.

%t (* we use function altdata[] from A277215 *)

%t a277875[n_]:=Map[#[[2]]&, altdata[2,n]]

%t Join[{1,7}, a277875[99]] (* sequence data *)

%Y Cf. A277215, A277874.

%K nonn

%O 0,2

%A _Hartmut F. W. Hoft_, Nov 03 2016

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Last modified June 2 19:52 EDT 2024. Contains 373045 sequences. (Running on oeis4.)