122760

Appears in sequences

• Numbers k whose decimal representation, read as a base-22 value and divided by k, yields an integer.at n=36A032575
• Tritriangular numbers: a(n) = binomial(binomial(n,2),2) = n*(n+1)*(n-1)*(n-2)/8.at n=32A050534
• Triangular numbers which are 8-almost primes.at n=14A076582
• Ninth column (m=8) of unsigned triangle A111595.at n=3A111782
• Triangular numbers that are sums of twin prime pairs.at n=17A165966
• Number of -2..2 arrays x(0..n-1) of n elements with sum zero and with zeroth through n-1st differences all nonzero.at n=12A200032
• Triangular numbers k whose divisors can be partitioned into three disjoint sets whose sums are all sigma(k)/3.at n=37A206025
• Average of amicable pairs (x,y), ordered by the smaller value x given in A002025.at n=15A275315
• Average of amicable pairs (x,y), ordered by the sum x+y given in A259953.at n=14A275316
• Triangular numbers k such that psi(k) is a square, where psi(k) is the Dedekind psi function (A001615).at n=31A292064
• a(n) = (3*n + 7)*Pochhammer(n, 5) / 4!.at n=8A293608
• Numbers that have exactly 7 representations as a k-gonal number, P(n,k) = n*((k-2)*n - (k-4))/2, k and n >= 3.at n=26A321157
• Triangular numbers such that the three numbers before it and the three numbers after it are squarefree.at n=14A374393
• Numbers k such that A380845(k) = 3*k.at n=11A380847