20481

Appears in sequences

• a(n) = (n-1)*2^n + 1.at n=11A000337
• Numbers that are the sum of 11 positive 11th powers.at n=10A004822
• Duplicate of A000337.at n=11A082753
• a(0) = 6; for n>0, a(n) = 2*a(n-1) - 1.at n=12A083575
• Triangle read by rows: T(n,k) is the number of ternary words of length n having k runs of consecutive 0's (0<=k<=ceiling(n/2)).at n=42A119808
• Triangle read by rows: T(n,k) = is the number of directed column-convex polyominoes of area n having along the lower contour exactly k reentrant corners, i.e., a vertical step that is followed by a horizontal step (n >= 1, k >= 0).at n=43A121466
• An 11th-order Fibonacci sequence: a(n) = a(n-1) + ... + a(n-11).at n=22A127624
• Largest number not the sum of n distinct nonzero squares.at n=33A129210
• Number of partitions of n into parts which are not digits of n in decimal representation.at n=49A136460
• Triangle read by rows, binomial transform of A122196.at n=43A152230
• a(n) = smallest k > 1 such that k-1 and k+1 together have n prime divisors.at n=17A155850
• a(n) = 20*n^2 + 1.at n=32A158493
• a(n) = 80*n^2 + 1.at n=16A158776
• Semiprimes q such that q^2-4 and q^2+4 are also semiprimes.at n=17A173084
• a(n) = 5*4^n+1.at n=6A199115
• a(n) = 5*8^n+1.at n=4A199553
• Triangle of coefficients of polynomials u(n,x) jointly generated with A210198; see the Formula section.at n=43A210197
• Semiprimes of the form 5*n^2 + 1.at n=21A212707
• Irregular triangle read by rows: coefficients of polynomials V_n(x), highest degree terms first.at n=57A257597
• Sum of numbers in the n-th antidiagonal of the reciprocity array of 3.at n=43A259583