a(n) is the least number k such that both k and k - s have n prime divisors, counted with multiplicity, where s is the sum of the decimal digits of k.
A381851
a(n) is the least number k such that both k and k - s have n prime divisors, counted with multiplicity, where s is the sum of the decimal digits of k.
Terms
- a(0) =10a(1) =20a(2) =40a(3) =80a(4) =224a(5) =448a(6) =2176a(7) =24640a(8) =98816a(9) =287744a(10) =3771392a(11) =5637632a(12) =6508544a(13) =323903488a(14) =1126252544a(15) =7698939904a(16) =20511260672a(17) =249460531200a(18) =857557762048a(19) =582799458304
External references
- oeis: A381851