31241

Appears in sequences

• a(0) = 1, a(1) = 4, and a(n) = a(n-1) + a(n-2) for n >= 2.at n=20A000285
• n written in fractional base 5/3.at n=41A024633
• Numerators of continued fraction convergents to sqrt(867).at n=4A042674
• Expansion of (1+2*x)/(1-3*x+x^2).at n=10A054486
• Fibonacci sequence with initial values a(0) = 3 and a(1) = 1.at n=21A104449
• Semiprimes in A033951.at n=27A113691
• a(n) = 1 + n + ((n-1)*n^2)/2.at n=40A218152
• y-values in the solution to x^2 - 20*y^2 = 176.at n=20A228208
• Array of coefficients a(k,n) of the formal power series A(k,x) read by upwards antidiagonals, where A(k,x) = ((2*k+1)*x+sqrt(1+4*k*(k+1)*x^2))/(1-x^2), k>=0.at n=61A277930
• a(n) = a(n-1) + 3*a(n-2) -2*a(n-3) - 2*a(n-4), where a(0) = 1, a(1) = 3, a(2) = 5, a(3) = 7.at n=20A295717
• Number of partitions of n into colored blocks of equal parts with colors from a set of size n such that the block with largest parts has the first color.at n=13A325916
• Number of entries in the eighth blocks of all set partitions of [n] when blocks are ordered by increasing lengths.at n=3A332948
• (2,2)-block array, B(2,1), of the Wythoff array (A035513), read by descending antidiagonals.at n=36A361994
• Consecutive states of the linear congruential pseudo-random number generator for 16-bit WATFOR/WATFIV when started at 1.at n=2A384158