25575

Appears in sequences

• Divisors of 2^20 - 1.at n=39A003529
• Number of segments created by diagonals of n-gon.at n=22A014629
• Maximum cycle length in differentiation digraph for n-bit binary sequences.at n=24A038553
• Odd numbers divisible by the palindromic sum of their prime factors (counted with multiplicity).at n=11A046359
• Number of primitive n X n real (0,1)-matrices.at n=4A070322
• a(1) = 3, a(2) = 4. a(n) = (largest composite which occurs earlier in sequence) + (largest prime which occurs earlier in sequence).at n=35A120365
• Least number k such that k*p(n)*(k*p(n)+1)-1, k*p(n)*(k*p(n)+1)+1, k*p(n)*(k*p(n)+3)-1 and k*p(n)*(k*p(n)+3)+1 are all primes, two pairs of twin primes, with p(i) = i-th prime.at n=34A139638
• Number of walks within N^2 (the first quadrant of Z^2) starting at (0,0), ending on the vertical axis and consisting of n steps taken from {(-1, 1), (0, 1), (1, -1)}.at n=14A151381
• Terms in A046034 which are pairwise products of terms in A046034.at n=25A153446
• a(n) = (2^A002326(n)-1)/(2*n+1).at n=20A165781
• Moebius inversion of a sequence related to powers of 2.at n=20A178738
• a(n) = floor((-1 + 2^n)/(1 + 2*n)).at n=19A191630
• a(n) = floor((1 + 2^n)/(1 + 2*n)).at n=19A191633
• a(n) = floor((1 + 4^n)/(1 + 4*n)).at n=9A191641
• a(n) = (1/n)*A204983(n).at n=40A204984
• Number of (n+3) X 7 0..1 matrices with each 4 X 4 subblock idempotent.at n=16A224564
• Number of triple-crossings of diagonals in the regular 2n-gon.at n=29A260417
• Numbers k such that (7*10^k + 71)/3 is prime.at n=30A270831
• Numbers k such that (2^ord(2, k) - 1)/k is prime, where ord(2, k) is the multiplicative order of 2 (mod k).at n=42A297362
• a(n) = ((-4)^((p-1)/4) - 1)/p, where p is the n-th prime congruent to 1 mod 4.at n=5A318898