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

3970902, 4851691, 7921800, 39022919, 102132857, 110468517, 368495972, 391099413, 395147912, 421129348, 452808398, 608389509, 667231451, 693386307, 698864465, 776218485, 1005771844, 1335351479, 1336652359, 1485470432

Offset: 1

Author

Giovanni Resta, Jan 15 2006

Keywords

• nonn

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)

Crossrefs

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