139656

Appears in sequences

• Doubly triangular numbers: a(n) = n*(n+1)*(n^2+n+2)/8.at n=32A002817
• Smallest triangular number having n^2 as divisor.at n=22A080983
• a(n) = n^2 * (n^2 - 1)/2.at n=22A083374
• a(n) = 9973*n + 10007.at n=13A101442
• a(n) = ((n-th prime)^4-(n-th prime)^2)/2.at n=8A138418
• Triangular numbers that are sums of twin prime pairs.at n=18A165966
• Let T(n) = n(n+1)/2 be the n-th triangular number (A000217); a(n) = T(8T(n)).at n=11A185096
• Number of 2 X 2 matrices with all terms in {0,1,...,n} and odd trace.at n=22A210379
• Triangular numbers T such that sum of the factorials of digits of T is prime.at n=33A242831
• Triangular numbers that are the product of a triangular number and a square number (both greater than 1).at n=10A253650
• Triangular numbers that are the product of a triangular number and an oblong number.at n=28A253652
• Numerators of coefficients of polynomials arising from applying the complete Bell polynomials to k!B_k(x)/(k*(k-1)) with B_k(x) the Bernoulli polynomials.at n=52A276996
• Table read by downward antidiagonals: T(n,k) is the number of tilings of the n X k cylinder up to horizontal reflections by two tiles that are each fixed under horizontal reflection.at n=31A368258