A163139 - OEIS

%I #11 Mar 04 2019 01:50:35

%S 1,1,1,1,10,10,10,10,10,10,10,10,10,1,10,10,10,10,10,10,10,10,10,1,10,

%T 10,10,10,10,10,10,10,10,1,10,10,10,10,10,10,10,10,10,1,10,10,10,10,

%U 10,10,10,10,10,1,10,10,10,10,10,10,10,10,10,1,10,10,10,10,10,10,10,10,10,1,10

%N First differences of A163128.

%C First differences of self numbers, minus 1.

%F a(n) = A163128(n+1) - A163128(n) = A003052(n+1) - A003052(n) - 1.

%e a(6) = 24 - 14 = 10.

%p A007953 := proc(n) add(d,d=convert(n,base,10)) ; end:

%p isA003052 := proc(n) for k from 1 to n do if k+A007953(k) = n then RETURN(false) ; fi; od: true; end:

%p A003052 := proc(n) option remember; if n = 1 then 1; else for a from procname(n-1)+1 do if isA003052(a) then RETURN(a) ; fi; od: fi; end:

%p for n from 1 to 100 do printf("%d,",A003052(n+1)-A003052(n)-1) ; od: # _R. J. Mathar_, Jul 31 2009

%Y Cf. A003052, A163128.

%K nonn,base

%O 1,5

%A _Juri-Stepan Gerasimov_, Jul 21 2009

%E Missing 10's inserted by _R. J. Mathar_, Jul 31 2009