Numbers n with the property that it is possible to write the base 2 expansion of n as concat(a_2,b_2), with a_2>0 and b_2>0 such that, converting a_2 and b_2 to base 10 as a and b, we have sigma(a)*sigma(b) = n.
A244079
Numbers n with the property that it is possible to write the base 2 expansion of n as concat(a_2,b_2), with a_2>0 and b_2>0 such that, converting a_2 and b_2 to base 10 as a and b, we have sigma(a)*sigma(b) = n.
Terms
- a(0) =28a(1) =120a(2) =162a(3) =196a(4) =868a(5) =1260a(6) =1302a(7) =1800a(8) =2016a(9) =2480a(10) =3780a(11) =4464a(12) =6804a(13) =7440a(14) =8370a(15) =9882a(16) =22200a(17) =32640a(18) =34290a(19) =35640a(20) =40640a(21) =73152a(22) =127008a(23) =187488a(24) =213776a(25) =489888a(26) =572880a(27) =602640a(28) =674082a(29) =1074528
External references
- oeis: A244079