200978

Appears in sequences

• Numbers n such that the sum_i (d_i^i) of the i-th powers of their sorted divisors d_1< d_2<...< n is prime.at n=12A180852
• Half the number of (n+1) X 2 binary arrays with no 2 X 2 subblock sum differing from a horizontal or vertical neighbor subblock sum by more than one.at n=8A184606
• T(n,k)=Half the number of (n+1)X(k+1) binary arrays with no 2X2 subblock sum differing from a horizontal or vertical neighbor subblock sum by more than one.at n=36A184614
• Numbers that decrease two times in succession when they are iteratively replaced by the "Look and Say" description (cf. A045918) of their prime factors, counted with multiplicity.at n=6A379455
• Number of proper prime powers (in A246547) that do not exceed primorial A002110(n).at n=12A380402