Consider a number of k digits n = d_(k)*10^(k-1) + d_(k-1)*10^(k-2) + … + d_(2)*10 + d_(1). Sequence lists the numbers n such that sigma(n) - n = Sum_{i=1..k-1}{sigma(Sum_{j=1..i}{d_(j)*10^(j-1)})} (see example below).
A240895
Consider a number of k digits n = d_(k)*10^(k-1) + d_(k-1)*10^(k-2) + … + d_(2)*10 + d_(1). Sequence lists the numbers n such that sigma(n) - n = Sum_{i=1..k-1}{sigma(Sum_{j=1..i}{d_(j)*10^(j-1)})} (see example below).
Terms
- a(0) =11a(1) =25a(2) =31a(3) =41a(4) =61a(5) =71a(6) =341a(7) =671a(8) =2119a(9) =10231a(10) =39579a(11) =52231a(12) =60341a(13) =402959a(14) =1288689a(15) =1393059a(16) =1956759a(17) =16752951a(18) =108659999a(19) =181704519a(20) =794033191a(21) =1062726071a(22) =3518397571a(23) =4062296851a(24) =4085227151a(25) =7015608139
External references
- oeis: A240895