23140

Appears in sequences

• Sum_{k<=n} (sigma(k)^2), where sigma(k) denotes the sum of the divisors of k A000203.at n=28A072379
• Round(1000*x), where x is the solution to x = 3^(n-x).at n=26A103537
• Number of weight-n binary n X n matrices that yield the all-ones matrix after repeatedly changing a 0 having at least two 1-neighbors to a 1.at n=5A146971
• Expansion of Product_{k>=1} (1 + 4*x^k).at n=21A261568
• Number of (n+1) X (4+1) arrays of permutations of 0..n*5+4 with each element having directed index change -1,1 -1,2 1,0 or 0,-1.at n=6A264546
• T(n,k)=Number of (n+1)X(k+1) arrays of permutations of 0..(n+1)*(k+1)-1 with each element having directed index change -1,1 -1,2 1,0 or 0,-1.at n=51A264550
• Number of (7+1)X(n+1) arrays of permutations of 0..n*8+7 with each element having directed index change -1,1 -1,2 1,0 or 0,-1.at n=3A264556
• Numbers m such that there exists a j for which m = Sum_{k=1..j} (m mod k), where k runs through the largest j primes less than m.at n=37A274422
• Solution of the complementary equation a(n) = a(n-1) + a(n-2) + b(n-1) + b(n-2) + n - 1, where a(0) = 1, a(1) = 2, b(0) = 3, and (a(n)) and (b(n)) are increasing complementary sequences.at n=16A294557
• Numbers with property that both the digit sum and the sum of the prime factors (counted with multiplicity) have only digits 0 and 1 in base 10.at n=18A297614
• Integers x such that [f(0), f(f(0)), ..., f(...f(0)...)] is a permutation of [0, 1, ..., k-1], where k is the number of digits in x and f(a) denotes the 0-based index of the first occurrence of the substring a in x.at n=18A307620
• Expansion of 1/Sum_{k>=0} x^(k^2).at n=46A317665
• a(n) is the index of the smallest n-gonal pyramidal number with binary weight n.at n=33A359092
• G.f. satisfies A(x) = 1 + x * (1 - x)^2 * A(x * (1 - x)).at n=11A360992
• a(n) is the smallest number which can be represented as the sum of 6 distinct positive n-th powers in exactly 3 ways, or -1 if no such number exists.at n=3A375330