22252

Appears in sequences

• Numbers having four 2's in base 10.at n=19A043500
• Numbers using only the digits 2 and 5, that are both curved and straight.at n=32A072961
• a(n) = Sum_{i=1..n} C(i+3,4)^2.at n=5A086023
• Lexicographically earliest sequence of increasing numbers whose digits satisfy the "Fractal Jump" rule using only the digits 2 and 5: keep the first digit "d" of the sequence, then jump over the next "d" digits and keep the digit "e" on which you have landed. Jump now over the next "e" digits and keep the digit "f" on which you have landed, etc. The succession "def..." of kept digits is the sequence itself.at n=15A105647
• Number triangle of sums of squared binomial coefficients.at n=49A110197
• Square array of Kekulé numbers for the mirror-symmetrical chevrons Ch(m,n), read by antidiagonals (m,n >= 0).at n=60A123349
• The fourth row of the ED1 array A167546.at n=14A167547
• G.f. A(x) satisfies A(A(x)) = (x+2*x^2)/(1-2*x-4*x^2).at n=13A199823
• Number of semistandard Young tableaux over all partitions of 5 with maximal element <= n.at n=10A210427
• Number of (3+2) X (n+2) 0..3 arrays with every 3 X 3 subblock row and diagonal sum equal to 0 3 5 6 or 7 and every 3 X 3 column and antidiagonal sum not equal to 0 3 5 6 or 7.at n=14A252387
• Numbers k such that 5*10^k + 21 is prime.at n=21A281839
• a(n) = Sum_{k = 0..n} binomial(n+k-1, k)^2.at n=5A333592