138237

Appears in sequences

• Numbers k such that k and k+1 have same sum of divisors.at n=28A002961
• n is equal to the number of 4s in all numbers <= n written in base 6.at n=19A014892
• Numbers k such that k and k+1 have the same sum but an unequal number of divisors.at n=18A054007
• Numbers k such that k and k+1 have the same sum of squarefree divisors, or sqf(k) = sqf(k+1), where sqf(k) = A048250(k).at n=32A063964
• Numbers k such that k and k+1 have the same sum of unitary and nonunitary divisors.at n=14A064729
• Numbers k such that sigmawt(k) = sigmawt(k+1), where sigmawt(k) is the sum of the divisors of k weighted by divisor multiplicity in k.at n=15A171183
• Numbers n such that sigma(n+1) - sigma(n) = k*n for some integer k, where sigma(n) = A000203 (sum of divisors of n).at n=38A223136
• Numbers k such that s(k) = s(k+1) where s(k) is the sum of unitary, squarefree divisors of k, including 1 (A092261).at n=25A327875
• Numbers k such that s(k) = s(k+1), where s(k) is the sum of recursive divisors of k (A333926).at n=27A333949
• Numbers m such that the delta(m) = abs(sigma(m+1)/(m+1) - sigma(m)/(m)) is smaller than delta(k) for all k < m.at n=33A335071
• Factor balanced numbers. See Comments for definition.at n=23A343153
• Number k such that A033634(k) = A033634(k+1).at n=29A349224
• Numbers k such that A051378(k) = A051378(k+1).at n=29A349283