522753

Appears in sequences

• Triangular numbers all of whose digits are primes.at n=7A111483
• a(n) = binomial(2^n-1,2).at n=10A134057
• Half the number of length n integer sequences with sum zero and sum of squares 288.at n=5A157544
• a(n) = ((2^b-1)/phi(n))*Sum_{d|n} Moebius(n/d)*d^(b-1) for b = 10.at n=1A160959
• a(n) = smaller member of n-th pair of distinct, positive, triangular numbers whose sum and difference are also triangular numbers.at n=19A185129
• Number of holes in a sheet of paper when you fold it n times and cut off the four corners.at n=19A274230
• Three-column array pPT read by rows: subsequence of primitive Pythagorean triples (x, y, z) with x = A153893^2 - A000079^2, y = 2*A153893*A000079, z = A153893^2 + A000079^2, ordered by increasing z.at n=24A334638
• Denominators in a harmonic triangle; q-analog of A126615, here q = 2.at n=53A377278