21252

Appears in sequences

• a(n) = Sum_{k = 0..n} binomial(n,k)^4.at n=5A005260
• Alkane (or paraffin) numbers l(8,n).at n=19A005995
• Theta series of A*_23 lattice.at n=80A023935
• Number of reversible strings with n-1 beads of 2 colors. 5 beads are black. String is not palindromic.at n=18A032092
• a(n) = 2*binomial(n,4).at n=24A034827
• Denominators of continued fraction convergents to sqrt(482).at n=7A041921
• Smallest composite which when sum of prime factors is repeatedly subtracted reaches a prime after n iterations.at n=30A053093
• One half of binomial coefficients C(2*n-4,5).at n=9A053132
• Column 2 of triangle A055907.at n=31A055908
• Triangle read by rows of numbers of paths in a lattice satisfying certain conditions.at n=50A071948
• Numbers k such that sopfr(k)=tau(k).at n=37A078511
• a(n) = number of partitions of n wherein the sum of the 1's is no more than the sum of the other parts.at n=36A083690
• Non-palindromic solutions to sigma(R(n)) = sigma(n), where R = A004086 is digit-reversal.at n=12A085329
• Numbers whose number of divisors equals the sum of their separate prime-power decompositions.at n=10A087004
• Triangle read by rows: T(n,k) is the number of noncrossing trees with root degree equal to k.at n=49A092276
• Gaps associated with the arithmetic progressions in A093365.at n=22A093366
• Gaps associated with the arithmetic progressions in A093365.at n=24A093366
• Gaps associated with the arithmetic progressions in A093365.at n=23A093366
• a(n) = (2/(n-1))*a(n-1) + ((n+5)/(n-1))*a(n-2) with a(0)=0 and a(1)=1.at n=42A096338
• a(1)=1. a(n) = a(n-1) + sum of the triangular numbers which are among the first (n-1) terms of the sequence.at n=37A100963