23345

Appears in sequences

• a(n) = n*(n+5)*(n+6)*(n+7)/24.at n=23A005587
• Fibonacci sequence beginning 1, 14.at n=17A022104
• Convolution of Lucas numbers and (F(2), F(3), F(4), ...).at n=14A023619
• Numbers n such that n = p + q with n*p*q = primorial number (A002110) (p <= q, p > 0, q > 0).at n=19A057035
• Smallest number k such that in its decimal representation the first n digits of Pi=3.14... are contained in 11^k.at n=9A096935
• Indices of primes in sequence defined by A(0) = 91, A(n) = 10*A(n-1) + 41 for n > 0.at n=19A101009
• Let e_n(k)>=0 denote the exponent of prime(k) in the prime power representation of n. The sequence lists 1 followed by numbers n for which e_n(2*i-1)=e_n(2*i), for all i>=1.at n=40A275407
• a(n) = (1/n) * Sum_{k=1..n} k * lcm(k,n).at n=45A344509
• Lexicographically earliest sequence of distinct terms > 0 such that the sum a(n) + a(n+1) is a substring of the concatenation (a(n), a(n+1)).at n=40A359482
• Triangular array read by rows. T(n,k) is the number of idempotent Boolean relation matrices with rank k, n >= 0, 0 <= k <= n.at n=19A363232
• Products k of 4 distinct primes (or tetraprimes) such that k has no squarefree neighbors.at n=35A364141
• Composite squarefree integers for which the sum of the squares of their factors is a square.at n=14A379780