26664

Appears in sequences

• Numbers n such that (phi(n) + 1) | sigma(n + 1), where phi is Euler's totient function A000010.at n=9A015775
• Powers of fourth root of 11 rounded to nearest integer.at n=17A018076
• Powers of fourth root of 11 rounded up.at n=17A018077
• a(n) = dot_product(1,2,...,n)*(4,5,...,n,1,2,3).at n=40A026040
• Decimal concatenations of the 38 quintuples (d1,d2,d3,d4,d5) with elements in {2,4,6} for which there exists a prime p >= 7 such that the differences between the 6 consecutive primes starting with p are (d1,d2,d3,d4,d5).at n=9A078870
• a(n) is the least number with n palindromic divisors.at n=23A087997
• a(n) = S1(n,3), where S1(n, t) = Sum_{k=0..n} (k^t * Sum_{j=0..k} binomial(n,j)).at n=6A089660
• Number of palindromic divisors of a(n) sets a new record.at n=16A093036
• a(1)=1; a(n) = the reversal of (a(n-1) + spd(a(n-1))), where spd(n) is the sum of d^d for d the digits of n (with 0^0 = 1).at n=3A121167
• Triangle of coefficients of polynomials u(n,x) jointly generated with A209768; see the Formula section.at n=51A209767
• Number of (n+1) X (1+1) 0..3 arrays with no 2 X 2 subblock having the sum of its diagonal elements less than the maximum of its antidiagonal elements.at n=2A251301
• Number of (n+1)X(3+1) 0..3 arrays with no 2X2 subblock having the sum of its diagonal elements less than the maximum of its antidiagonal elements.at n=0A251303
• T(n,k)=Number of (n+1)X(k+1) 0..3 arrays with no 2X2 subblock having the sum of its diagonal elements less than the maximum of its antidiagonal elements.at n=3A251308
• T(n,k)=Number of (n+1)X(k+1) 0..3 arrays with no 2X2 subblock having the sum of its diagonal elements less than the maximum of its antidiagonal elements.at n=5A251308
• Smallest base b > 1 such that both prime(n) and prime(n+1) are base-b Wieferich primes, i.e., p = prime(n) satisfies b^(p-1) == 1 (mod p^2) and q = prime(n+1) satisfies b^(q-1) == 1 (mod q^2).at n=34A259075
• a(n) = Sum_{k=0..n} binomial(k+n+3,k)*binomial(2*n+1,n-k).at n=5A278596
• Decimal representation of the x-axis, from the left edge to the origin, of the n-th stage of growth of the two-dimensional cellular automaton defined by "Rule 398", based on the 5-celled von Neumann neighborhood.at n=14A281758
• Triangle of Touchard's chord enumerating polynomial coefficients [x^k] P_n(x).at n=54A322456
• Numbers k such that k*sod(k) and k/sod(k) are both palindromes, where sod(k) denotes the sum of digits of k (A007953).at n=4A334533
• Maximum number of copies of a 12345 permutation pattern in an alternating (or zig-zag) permutation of length n + 7.at n=16A339355