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A115171
Positive numbers that are not the sum of a triangular number, a square and a positive Fibonacci number.
10
3970902, 4851691, 7921800, 39022919, 102132857, 110468517, 368495972, 391099413, 395147912, 421129348, 452808398, 608389509, 667231451, 693386307, 698864465, 776218485, 1005771844, 1335351479, 1336652359, 1485470432
OFFSET
1,1
COMMENTS
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.
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
LINKS
Donovan Johnson, Table of n, a(n) for n = 1..176 (terms < 4*10^10)
KEYWORD
nonn
AUTHOR
Giovanni Resta, Jan 15 2006
STATUS
approved