23276

Appears in sequences

• 4-dimensional pyramidal numbers: a(n) = n^2*(n^2-1)/12.at n=23A002415
• Number of binary rooted trees of height n requiring 3 registers.at n=5A006223
• Number of possible rook moves on an n X n chessboard.at n=22A035006
• Sequence A001033 gives the numbers n such that the sum of the squares of n consecutive odd numbers x^2 + (x+2)^2 + ... +(x+2n-2)^2 = k^2 for some integer k. For each n, this sequence gives the least value of k.at n=34A056132
• Sum of absolute values of coefficients of expansion of (1-x)(1-x^2)(1-x^3)...(1-x^n).at n=39A061553
• Numbers n such that sopf(sigma(n)) = sigma(sopf(n)), where sopf(x) = sum of the distinct prime factors of x.at n=33A076532
• Smallest multiple of n^2 beginning with n.at n=22A078210
• An interleaved sequence of pyramidal and polygonal numbers.at n=44A081283
• a(n) = (2/(n-1))*a(n-1) + ((n+5)/(n-1))*a(n-2) with a(0)=0 and a(1)=1.at n=43A096338
• Triangular array formed by the Mersenne numbers.at n=48A110441
• Riordan array (1/(1+3x+2x^2),x/(1+3x+2x^2)).at n=48A111806
• A002415 and A052472 interlaced.at n=45A117651
• Triangle read by rows: T(n,k) is the number of full binary trees with n internal vertices and Strahler number k.at n=27A127151
• a(n) = denominator of b(n): b(n) = the maximum possible value for a continued fraction whose terms are a permutation of the terms of the simple continued fraction for H(n) = sum{k=1 to n} 1/k, the n-th harmonic number.at n=13A129083
• a(n) = (prime(n)^4 - prime(n)^2)/12.at n=8A138422
• Antidiagonal sums of the triangle A120070.at n=43A143785
• 15-gonal (or pentadecagonal) pyramidal numbers: a(n) = n*(n+1)*(13*n-10)/6.at n=22A177890
• Number of 5-step E, S, NW and NE-moving king's tours on an n X n board summed over all starting positions.at n=12A187588
• Number of n X 5 binary arrays without the pattern 0 1 diagonally or vertically.at n=12A188839
• Number of n X 4 0..1 arrays avoiding 0 0 1 and 0 1 0 horizontally and 0 1 1 and 1 1 0 vertically.at n=6A207560