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

1, 2, 3, 6, 7, 14, 21, 42, 43, 86, 129, 258, 301, 602, 903, 1806, 1849, 3698, 5547, 11094, 12943, 25886, 38829, 77658, 77659, 155318, 232977, 465954, 543613, 1087226, 1630839, 3261678, 3339337, 6678674, 10018011, 20036022, 23375359, 46750718, 70126077, 140252154

Offset

1,2

Comments

In contrast, A000079(n) is the lexicographically *largest* sequence such that a(n) - a(n-1) is the largest proper divisor of a(n).

Sequence is infinite because A060681 is surjective.

Links

Table of n, a(n) for n=1..40.

Formula

a(n) is the smallest number m such that m - A032742(m) = a(n-1), n > 1.

Maple

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

Prog

(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

Crossrefs

Cf. A105017, A064097, A175125, A060681.

Sequence in context: A018748 A018258 A325094 * A018379 A245479 A294524

Adjacent sequences: A191611 A191612 A191613 * A191615 A191616 A191617

Keyword

nonn

Author

Jaroslav Krizek, Jun 09 2011

Extensions

More terms from Rémy Sigrist, Apr 24 2021

Status

approved