49770

Appears in sequences

• Triangular numbers which are 6-almost primes.at n=30A076580
• Triangular numbers for which the sum of the digits is a cube.at n=18A117803
• Triangular numbers that are sandwiched between two semiprimes; or triangular numbers t such that t-1 and t+1 are both semiprime.at n=16A121898
• Triangular sequence defined by T(n, m) = (r^(n-m)*q^m + r^m*q^(n-m))*b(n), where b(n) = coefficients of p(x, n) = 2^n*(1-x)^(n+1) * LerchPhi(x, -n, 1/2), and r=2, q=3.at n=16A154696
• Triangular sequence defined by T(n, m) = (r^(n-m)*q^m + r^m*q^(n-m))*b(n), where b(n) = coefficients of p(x, n) = 2^n*(1-x)^(n+1) * LerchPhi(x, -n, 1/2), and r=2, q=3.at n=19A154696
• a(n) = (2*n^3 + 5*n^2 - 7*n)/2.at n=35A162261
• Triangular numbers k whose divisors can be partitioned into three disjoint sets whose sums are all sigma(k)/3.at n=23A206025
• Least triangular number t such that t = prime(n)*triangular(m) for some m>0, or 0 if no such t exists.at n=21A225503
• Least triangular number of the form p*triangular(n) where p is a prime number, or 0 if no such triangular number exists.at n=35A225789
• Number of (n+2)X(3+2) 0..3 arrays with every 3X3 subblock row and column sum equal to 0 3 5 6 or 7 and every 3X3 diagonal and antidiagonal sum not equal to 0 3 5 6 or 7.at n=8A252143
• Numbers n for which 2 < A257993(A276086(A276086(n))) < A257993(n), where A276086 converts the primorial base expansion of n into its prime product form, and A257993 returns the index of the least prime not present in its argument.at n=33A328762
• Triangular numbers that are sandwiched between two squarefree semiprimes.at n=14A375384
• Semiperimeter of the unique primitive Pythagorean triple whose inradius is the n-th prime and whose short leg is an odd number.at n=36A382070
• Primitive terms of A023197 that are of the form 4u+2.at n=33A388020