Tuesday, October 9, 2012

7011

7011 = 3 x 3 x 19 x 41.

7011 yields a prime whenever 1 is inserted anywhere in the number (A068679 and A216165): 17011, 71011, and 70111 are all primes.

7011 is the sum of three cubes of distinct primes (A138853 and A138854): 7011 = 193 + 53 + 33.

7011 is the number of 16-crossing knots with symmetry group Z2 (A052412).

7011 is the number of 5 x 5 arrays of squares of integers, symmetric about the main diagonal, with all rows summing to 36 (A156385).


Source: On-Line Encyclopedia of Integer Sequences

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