23455

Appears in sequences

• Integers are written in the form abcd...n where "a" means "At position a in this integer there is a digit b"; "b" means: "at position b there is a digit c"; "c" means: "at position c there is a digit d"; ... and "n" means nothing. No repetitions are allowed (like in the integer 111).at n=42A105958
• Number of different values assumed by a/b+c/d as a,b,c,d range between 1 and n.at n=21A119868
• a(n) = (4*n^3 - 12*n^2 + 14*n + 3)/3.at n=27A161703
• Representation of n = sum_k b_k*(k!!) in the double-factorial base by some b_k-fold concatenation of the indices k.at n=42A181521
• G.f.: (x+x^3+x^4)/(1-x-x^3-2*x^4).at n=20A236392
• Partial sums of the number of active (ON, black) cells in n-th stage of growth of two-dimensional cellular automaton defined by "Rule 553", based on the 5-celled von Neumann neighborhood.at n=28A272848
• Partial sums of A299257.at n=31A299263
• G.f. A(x) satisfies: 5*x = Sum_{n=-oo..+oo} (-1)^n * x^(n*(n+1)/2) * A(x)^n.at n=5A355355