23030

Appears in sequences

• Positive numbers k such that (k+1)*(k+2)*(k+3)*(k+4)/(k+(k+1)+(k+2)+(k+3)+(k+4)) is an integer.at n=27A032795
• a(n) = a(n-1) + a(m) for n >= 4, where m = 2*n - 2 - 2^(p+1) and p is the unique integer such that 2^p < n - 1 <= 2^(p+1), starting with a(1) = a(2) = 1 and a(3) = 2.at n=38A050031
• Largest coefficient in expansion of (1 + x + x^2 + ... + x^(n-1))^5 = ((1-x^n)/(1-x))^5, i.e., the coefficient of x^floor(5*(n-1)/2) and of x^ceiling(5*(n-1)/2); also number of compositions of floor(5*(n+1)/2) into exactly 5 positive integers each no more than n.at n=14A077044
• Sequence A014486 shown in base 4.at n=29A085185
• Triangle T(n, k) read by rows; given by [0, 1, 0, 1, 0, 1, ...] DELTA [1, 1, 2, 5, 14, 42, 132, 429, 1430, ...] (A000108) where DELTA is Deléham's operator defined in A084938.at n=32A085845
• 4-Smith numbers.at n=28A103125
• Expansion of (x-5*x^2+11*x^3-12*x^4+7*x^5-2*x^6+x^7) / (1-6*x+15*x^2-20*x^3+15*x^4-6*x^5+x^6).at n=22A221948
• Numbers k such that 435*2^k+1 is prime.at n=46A323146