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Single Curio View: (Seek other curios for this number) 666 = (3*5)^{2} + (3*7)^{2}, written with all the singledigit primes. Note that 666, which is formed from the triangular number 6 repeated 3 (the only prime triangular number) times, is the smallest triangular number n = a^{2} + b^{2} such that a, b and a+b are triangular numbers. [Capelle]
Submitted: 20090509 05:50:47; Last Modified: 20090509 10:31:52.
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