53301

Appears in sequences

• Triangular numbers whose digit permutations yield at least two further triangular numbers.at n=31A069674
• Triangular numbers whose sum of aliquot divisors is a prime number.at n=26A083676
• Triangular numbers in which the sum of the external digits equals the sum of the internal digits.at n=17A088289
• Triangular numbers for which the sum of the digits is a pentagonal number.at n=29A117305
• Triangular numbers t such that all the digits needed to write the consecutive triangular numbers from 0 to t fill exactly an equilateral triangle (no holes, no overlaps).at n=21A158030
• a(n) = Sum_{d divides n} d*(n/d)^(d-1).at n=25A167531
• Triangular numbers n with digits d_1, d_2, ..., d_k such that d_1*(d_1+1)/2 + ... + d_k*(d_k+1)/2 is a triangular number.at n=38A254957
• a(n) = A000217(A000217(n)+1).at n=25A267707
• The first of three consecutive triangular numbers the sum of which is equal to the sum of three consecutive primes.at n=28A298168
• Composite numbers k coprime to 13 such that k divides A006190(k-Kronecker(13,k)).at n=39A327653