[seqfan] Re: Possible error in A190660

[Wouter Meeussen]

interval 
]1/2 , 1] :  1  :  t(1) = 1
]1 , 2]    :   0
]2 , 4]    :   1  :  t(2) = 2
]4 , 8]    :   1  :  t(3) = 6
]8 , 16]  :   2  :  t(4) = 10 ; t(5) = 15
etc

no?

Wouter.


-----Original Message----- 
From: Jeremy Gardiner 
Sent: Saturday, August 10, 2013 4:12 PM 
To: Sequence Fanatics Discussion list 
Subject: [seqfan] Possible error in A190660 

A190660 Number of triangular numbers T(k) between powers of 2, 2^(n-1) <
T(k) <= 2^n
1, 0, 1, 1, 2, 2, 3, 5, 7, 9, 13, 19, 27, 37, 53, 75, 106, 150, ...

I calculate:
1, 0, 1, 1, 1, 2, 2, 3, 5, 7, 9, 13, 19, 27, 37, 53, 75, 106, 150, ...

Being first differences of A(n) = round(sqrt(2)^n), n = 0,1,...

A(n) = 1, 1, 2, 3, 4, 6, 8, 11, 16, 23, 32, 45, 64, 91, 128, 181

Cf. A057048

- Please can someone verify?

Thanks,
Jeremy



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