18970

Appears in sequences

• Weird numbers: abundant (A005101) but not pseudoperfect (A005835).at n=32A006037
• a(n) = s(1)t(n) + s(2)t(n-1) + ... + s(k)t(n-k+1), where k = [ n/2 ], s = (Fibonacci numbers), t = (primes).at n=23A025088
• Number of primitive (period n) periodic palindromic structures using exactly three different symbols.at n=19A056519
• Numbers k such that 80*R_k + 3 is prime, where R_k = 11...1 is the repunit (A002275) of length k.at n=22A056694
• Unitary weird numbers: unitary abundant (A034683) but not unitary pseudoperfect (A293188).at n=29A064114
• Numbers in ascending order formed by using all the digits of the next n numbers.at n=26A081991
• Negabinary Keith numbers.at n=19A188381
• Bi-unitary weird numbers: bi-unitary abundant numbers (A292982) that are not bi-unitary pseudoperfect (A292985).at n=34A292986
• Infinitary weird numbers: infinitary abundant numbers (A129656) that are not infinitary pseudoperfect numbers (A306983).at n=35A306984
• Sequence lists numbers k > 1 such that k^4 == d(k) (mod sigma(k)), where d = A000005 and sigma = A000203.at n=18A323251
• Total sum of composite parts in all partitions of n.at n=25A326982
• Möbius transform of A341512, sigma(n)*A003961(n) - n*sigma(A003961(n)).at n=63A346239
• Nonexponential weird numbers: nonexponential abundant numbers (A348604) that are not equal to the sum of any subset of their nonexponential divisors.at n=26A348631
• (1+e)-weird numbers: (1+e)-abundant numbers k such that no subset of the aliquot (1+e)-divisors of k sums to k.at n=27A349285
• Determinant of n X n Fibonacci word matrix.at n=27A370724
• Euler transform of A373216.at n=34A373297