47058

Appears in sequences

• Primary pseudoperfect numbers: numbers n > 1 such that 1/n + sum 1/p = 1, where the sum is over the primes p | n.at n=4A054377
• Triangle T(n,k) read by rows: T(n,k) = (k-1)*T(n-1,k) + (n-k+2)*T(n-1, k-1), with T(n,1)=1, for 1 <= k <= n, n >= 1.at n=39A157011
• a(n) = 49*n^2 - n.at n=30A157923
• a(n) = 961*n^2 - 31.at n=6A158679
• Number of binary strings of length n with no substrings equal to 0001 1011 or 1100.at n=20A164489
• Composite numbers m such that (m'+1)' = m', where m' = A003415(m) is the arithmetic derivative of m.at n=4A185222
• Numbers n that can be expressed as the sum of the arithmetic derivatives of k previous numbers starting from n for some k >= 1.at n=9A187807
• Numbers n that can be expressed as the sum of the arithmetic derivatives of k consecutive numbers starting from n for some k.at n=14A195333
• Number of ways to place 3n nonattacking kings on a vertical cylinder 6 X 2n.at n=7A195591
• Number of ways to place 8n nonattacking kings on a 16 X 2n cylindrical chessboard.at n=2A195652
• Numbers m such that (m'+1)' = m-1, where m' is the arithmetic derivative of m.at n=11A203618
• List of integers m>0 with m-1 and m+1 both prime, and m-2, m, m+2 all practical.at n=14A209236
• Numbers that can be expressed as the sum of their first k consecutive arithmetic derivatives for some k > 1.at n=8A216384
• Numbers k such that the last 9 digits of the k-th Lucas number are 1-9 pandigital.at n=9A216488
• Numbers k such that k = sigma(k'), where k' is the arithmetic derivative of k.at n=3A230165
• Numbers n such that 1^(k*n) + 2^(k*n) + ... + (k*n)^(k*n) == k (mod k*n) for some k; that is, numbers n such that A031971(k*n) == k (mod k*n) for some k.at n=5A230311
• Prime power pseudoperfect numbers: numbers m > 1 such that 1/m + Sum 1/p^k = 1, where the sum is over the prime powers p^k | m.at n=42A283423
• 1-Sondow numbers: numbers j such that p divides j/p + 1 for every prime divisor p of j.at n=5A349193
• Products of 5 distinct primes that are sandwiched between twin prime numbers.at n=30A376380
• Smallest k for which A385731(k) = n.at n=5A386436