login
Infinite sum of the odd numbers, compacted (see the Comments line for an explanation).
0

%I #5 Aug 16 2020 13:01:04

%S 4,12,20,28,57,203,76,129,371,124,201,219,237,623,505,327,2489,1099,

%T 332,865,543,1337,2743,452,1165,723,1757,1315,813,831,849,2051,604,

%U 921,939,10757,1915,5213,2095,3017,2215,5993,2395,1461,6539,2605,17267,2965,1803,1821,1839,1857,12179,1324,8801

%N Infinite sum of the odd numbers, compacted (see the Comments line for an explanation).

%C When the successive terms of the present sequence are expressed as the sum of k>1 consecutive odd numbers and added, the end result will be 1 + 3 + 5 + 7 + 9 + 11 + 13 + 15 + 17...... (conjectured to extend ad infinitum).

%C This is the lexicographically earliest sequence of distinct positive terms with this property.

%C The equivalent sequence with sums of consecutive even numbers is simply A336897 where every term is doubled.

%e The 1st term is 4 and 4 = 1+3.

%e The 2nd term is 12 and 12 = 5+7.

%e The 3rd term is 20 and 20 = 9+11.

%e The 4th term is 28 and 28 = 13+15.

%e The 5th term is 57 and 57 = 17+19+21; etc.

%e (The 5th term is NOT 36 as 36 can be expressed as the sum of k>1 consecutive odd numbers in more than one way: 36 = 17+19 and 36 = 1+3+5+7+9+11).

%Y Cf. A336897, A337094.

%K base,nonn

%O 1,1

%A _Eric Angelini_ and _Jean-Marc Falcoz_, Aug 15 2020