54145

Appears in sequences

• a(n) = floor(C(n,4)/5).at n=52A011795
• Composite palindromes divisible by the sum of their prime factors (counted with multiplicity).at n=8A046348
• a(n) = T(n) concatenated with reverse(T(n)) divided by 11, where T(n) is the n-th triangular number.at n=34A084008
• a(0)=0, a(1)=1, a(n)=((2*n-1)*a(n-1)-5*n*a(n-2))/(n-1).at n=13A102840
• Palindromes n such that n+(product of digits of n) gives a larger palindrome.at n=19A114341
• Nonprime numbers k such that k divides 3^((k+1)/2) - 2^((k+1)/2) - 1.at n=16A130062
• a(n) = n*(n+1)*(8*n + 1)/6.at n=34A132124
• Number of nondecreasing integer sequences of length 8 with sum zero and sum of absolute values 2n.at n=23A158142
• Number of n X 2 arrays of the minimum value of corresponding elements and their horizontal, vertical or antidiagonal neighbors in a random, but sorted with lexicographically nondecreasing rows and nonincreasing columns, 0..2 n X 2 array.at n=34A219680
• a(n) = binomial(5*n+7, 4)/5 for n >= 0.at n=9A238472
• Palindromes of the form 4n + 1 that are divisible by 5.at n=32A256704
• Occurrences of decrease of the probability density P(n) of coprime numbers k,m, satisfying 1 <= k <= a(n) and 1 <= m <= a(n), and a(n) congruent to 1 (mod 2) and a(n) not congruent to 3 (mod 6).at n=20A280879
• Smallest number k such that A049559(k) / A187730(k) = n.at n=23A284440
• Nonsquarefree numbers n = p_1^s_1...p_m^s_m (m > 1) such that (p_i^s_i - 1) | n-1 for all 0 < i <= m.at n=3A292815
• Numbers that have exactly 7 representations as a k-gonal number, P(n,k) = n*((k-2)*n - (k-4))/2, k and n >= 3.at n=9A321157
• Odd composite numbers k such that Sum_{i=1..k-1} 2^i * i^(k-2) == Sum_{i=1..(k-1)/2} i^(k-2) (mod k).at n=28A373734