A081513 - OEIS

%I #30 Oct 24 2024 09:24:28

%S 1,0,3,6,12,8,24,20,28,40,40,30,60,45,60,120,90,72,72,168,240,180,144,

%T 168,168,216,420,315,210,420,420,336,432,1260,840,840,504,504,315,480,

%U 540,2520,2520,1680,1680,1260,1260,1008,720,2520,2520,1890,1512,945,3360

%N a(2)=0; for n != 2, let m = A081512(n), then a(n) = value of d_n in the lexicographically earliest set of n distinct divisors d_1, ..., d_n of m with d_1 + ... + d_n = m.

%H David A. Corneth, <a href="/A081513/b081513.txt">Table of n, a(n) for n = 1..552</a>

%e The lexicographically earliest solutions are:

%e ..n....m: d_1 d_2 ... d_n

%e -------------------------

%e ..1....1: 1

%e ..2....0: - -

%e ..3....6: 1, 2, 3

%e ..4...12: 1, 2, 3, 6

%e ..5...24: 1, 2, 3, 6, 12

%e ..6...24: 1, 2, 3, 4, 6, 8

%e ..7...48: 1, 2, 3, 4, 6, 8, 24

%e ..8...60: 1, 2, 3, 4, 5, 10, 15, 20

%e ..9...84: 1, 2, 3, 4, 6, 7, 12, 21, 28

%e .10..120: 1, 2, 3, 4, 5, 6, 15, 20, 24, 40

%e ...

%Y Cf. A081512, A081514.

%Y See also A081515, A081516, A081517, A081521.

%K nonn

%O 1,3

%A _Amarnath Murthy_, Mar 27 2003

%E Corrected by Caleb M. Shor (cshor(AT)bates.edu), Sep 26 2007

%E Terms a(8) onwards from _Jinyuan Wang_, May 23 2020

%E Definition clarified by _N. J. A. Sloane_, May 23 2020, following suggestions from _Jinyuan Wang_.