25680

Appears in sequences

• First of triples of consecutive happy numbers, i.e., the first of three consecutive integers each of which is a happy number (A007770).at n=24A072494
• Numbers k such that d(phi(k)) = phi(d(k)), where d=A000005 and phi=A000010.at n=37A078148
• Numbers that can be expressed as the difference of the squares of primes in exactly five distinct ways.at n=26A092001
• a(n) = 16*n^2 + 2*n.at n=39A158056
• Number of -5..5 arrays x(0..n-1) of n elements with zero sum and no two consecutive declines, no adjacent equal elements, and no element more than one greater than the previous (random base sawtooth pattern).at n=12A200178
• Number of (w,x,y) with all terms in {0,...,n} and |w-x| != |x-y|.at n=29A212960
• Triangular array read by rows: T(n,k) is the number of f:{1,2,...,n}->{1,2,...,n} with exactly 2k elements that have a preimage of even (possibly zero) cardinality; n>=0, 0<=k<=floor(n/2).at n=14A225942
• Number of length 4+2 0..n arrays with every three consecutive terms having the sum of some two elements equal to twice the third.at n=40A248437
• Number of 5 X n 0..1 arrays with no element equal to more than two of its horizontal, diagonal or antidiagonal neighbors, with the exception of exactly one element, and with new values introduced in order 0 sequentially upwards.at n=7A281404
• Triangle read by rows: T(n,k) is the number of chiral pairs of cycles of length n (1) with a color pattern of exactly k colors or equivalently (2) partitioned into k nonempty subsets.at n=72A320647