cp's OEIS Frontend

A191614 The lexicographically earliest sequence such that a(n) - a(n-1) is the largest proper divisor of a(n).

%I A191614 #15 Apr 24 2021 12:09:26
%S A191614 1,2,3,6,7,14,21,42,43,86,129,258,301,602,903,1806,1849,3698,5547,
%T A191614 11094,12943,25886,38829,77658,77659,155318,232977,465954,543613,
%U A191614 1087226,1630839,3261678,3339337,6678674,10018011,20036022,23375359,46750718,70126077,140252154
%N A191614 The lexicographically earliest sequence such that a(n) - a(n-1) is the largest proper divisor of a(n).
%C A191614 In contrast, A000079(n) is the lexicographically *largest* sequence such that a(n) - a(n-1) is the largest proper divisor of a(n).
%C A191614 Sequence is infinite because A060681 is surjective.
%F A191614 a(n) is the smallest number m such that m - A032742(m) = a(n-1), n > 1.
%p A191614 A191614 := proc(n) option remember; if n = 1 then 1; else for m from 1 do if m-A032742(m) = procname(n-1) then return m; end if; end do: end if; end proc: # _R. J. Mathar_, Jun 13 2011
%o A191614 (PARI) p=0; for (v=1, 140252154, if (v%(v-p)==0 && (p==0 || (d=divisors(v))[#d-1]==v-p), print1 (p=v ", "))) \\ _Rémy Sigrist_, Apr 24 2021
%Y A191614 Cf. A105017, A064097, A175125, A060681.
%K A191614 nonn
%O A191614 1,2
%A A191614 _Jaroslav Krizek_, Jun 09 2011
%E A191614 More terms from _Rémy Sigrist_, Apr 24 2021