156520

Appears in sequences

• Theta series of A_7 lattice.at n=22A008447
• Expansion of 1/((1-3*x)*(1-4*x)*(1-9*x)).at n=5A016909
• Average theta series of odd unimodular lattices of dimension 15 (multiplied by 43).at n=3A029816
• a(n) = n*(n^2 - 1)*(n + 2)*(n^2 + 4*n + 6)/72.at n=14A054563
• Triangular numbers whose digit reversal is also a triangular number.at n=24A061455
• Nonpalindromic triangular numbers whose digit reversal is also a triangular number (possibly with fewer digits).at n=10A069673
• a(1) = 0, then smallest triangular number such that a(n+1)- a(n) is a palindrome.at n=32A075057
• Triangular numbers whose sum of squared digits is also triangular.at n=33A094890
• Least triangular number whose digit permutations yield exactly n further triangular numbers.at n=5A095870
• Triangular numbers whose digit reversal is a brilliant number (A078972).at n=12A115678
• Numbers that set records for number of divisors of n(n-1).at n=31A192488
• Numbers that have exactly 8 representations as a k-gonal number, P(m,k) = m*((k-2)*m - (k-4))/2, k and m >= 3.at n=5A321158
• Expansion of x^2*(10-5*x+x^2)/((1-x)^4*(1-x^2)).at n=32A331429