31878

Appears in sequences

• Expansion of theta series of {E_7}* lattice in powers of q^(1/2).at n=36A003781
• Degrees of irreducible representations of Conway group Co3.at n=24A003910
• Degrees of irreducible representations of Conway group Co2.at n=17A003911
• Expansion of theta series of E_7 lattice in powers of q^2.at n=9A004008
• a(n) is the number of Dyck paths of semilength n+6 having its first peak at height n+1.at n=14A005557
• Nonzero coefficients in theta series of {E_7}* lattice.at n=18A030443
• a(n) = (binomial(2*n, n)^2 + binomial(2*n, n))/2.at n=5A037967
• Tritriangular numbers: a(n) = binomial(binomial(n,2),2) = n*(n+1)*(n-1)*(n-2)/8.at n=23A050534
• Consider 2n tennis players; a(n) is the number of matches needed to let every possible pair play each other.at n=10A062346
• Triangular numbers which are products of triangular numbers larger than 1.at n=27A068143
• Triangular numbers which are 6-almost primes.at n=22A076580
• Triangular numbers with palindromic indices.at n=34A089717
• Triangle, read by rows, where T(n,k) = C(n,k)*(C(n,k) + 1)/2, n>=k>=0.at n=60A107105
• Triangular numbers that are the product of 2 palindromes greater than 1.at n=27A115744
• Triangular numbers n divisible by the number of triangular numbers smaller than n.at n=40A117519
• Triangular numbers for which the sum of the digits is a cube.at n=11A117803
• Triangular numbers that are sandwiched between two semiprimes; or triangular numbers t such that t-1 and t+1 are both semiprime.at n=13A121898
• Number of walks within N^3 (the first octant of Z^3) starting at (0,0,0) and consisting of n steps taken from {(-1, -1, 0), (-1, 0, 0), (0, 0, -1), (1, 0, 1), (1, 1, -1)}.at n=9A149333
• Number of walks within N^3 (the first octant of Z^3) starting at (0,0,0) and consisting of n steps taken from {(-1, -1, 1), (-1, 0, 1), (0, 1, -1), (1, 0, 0), (1, 0, 1)}.at n=8A150458
• Triangle read by rows: T(n,k) = (4k+3)/(n+2k+2)*binomial(2n,n+2k+1).at n=40A158483