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A115171 Positive numbers that are not the sum of a triangular number, a square and a positive Fibonacci number. 10

%I #5 Mar 30 2012 17:40:34

%S 3970902,4851691,7921800,39022919,102132857,110468517,368495972,

%T 391099413,395147912,421129348,452808398,608389509,667231451,

%U 693386307,698864465,776218485,1005771844,1335351479,1336652359,1485470432

%N Positive numbers that are not the sum of a triangular number, a square and a positive Fibonacci number.

%C Comment from Kurt Foster, Jan 20 2009: If one is allowed to use the Fibonacci number zero, then many of these terms disappear. For example, one has 4851691 = 1885^2 + 1611*1612/2 + F_0, 7921800 = 1923^2 + 2906*2907/2 + F_0. See A144642.

%C Since the number of integers up to B of the form x^2+T_y is about a constant times B/sqrt(log B), heuristics predict that the sequence should be infinite. - Bjorn Poonen, in a posting to the Number Theory List, Dec 22 2008

%H Donovan Johnson, <a href="/A115171/b115171.txt">Table of n, a(n) for n = 1..176</a> (terms < 4*10^10)

%Y Cf. A115172, A115173, A115174, A115175, A115176, A115177, A144642.

%K nonn

%O 1,1

%A _Giovanni Resta_, Jan 15 2006

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Last modified April 24 10:11 EDT 2024. Contains 371935 sequences. (Running on oeis4.)