cp's OEIS Frontend

This is a front-end for the Online Encyclopedia of Integer Sequences, made by Christian Perfect. The idea is to provide OEIS entries in non-ancient HTML, and then to think about how they're presented visually. The source code is on GitHub.

A355702 a(1) = 1, a(2) = 2; for n > 2, a(n) is the smallest positive number that has not yet appeared that has the same number of prime divisors as the sum a(n-2) + a(n-1).

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%I A355702 #12 Jul 23 2022 09:54:27
%S A355702 1,2,3,5,8,7,4,11,6,13,17,12,19,23,18,29,31,16,37,41,20,43,27,28,9,47,
%T A355702 24,53,10,30,36,42,44,14,15,59,21,32,61,22,67,71,45,50,25,52,26,63,73,
%U A355702 40,79,33,48,54,66,72,68,56,70,60,75,81,84,76,64,88,90,34,78,80,35,38,83,39,46,49,51
%N A355702 a(1) = 1, a(2) = 2; for n > 2, a(n) is the smallest positive number that has not yet appeared that has the same number of prime divisors as the sum a(n-2) + a(n-1).
%C A355702 In the first 500000 terms on seventeen occasions the sum of the previous two terms equals the next term, these terms being 3, 5, 8, 11, 100,... ,131072, 262144. It in unknown if there are infinitely many such terms. In the same range there are seventy-three fixed points; see A356017. The sequence is conjectured to be a permutation of the positive integers.
%H A355702 Scott R. Shannon, <a href="/A355702/a355702_1.png">Image of the first 500000 terms</a>. The green line is y = n.
%e A355702 a(4) = 5 as a(2) + a(3) = 2 + 3 = 5 which has one prime divisor, and 5 is the smallest unused number that has one prime divisor.
%e A355702 a(6) = 7 as a(4) + a(5) = 5 + 8 = 13 which has one prime divisor, and 7 is the smallest unused number that has one prime divisor.
%e A355702 a(7) = 4 as a(5) + a(6) = 8 + 7 = 15 which has two prime divisors, and 4 is the smallest unused number that has two prime divisors.
%Y A355702 Cf. A356017, A001222, A355647, A355649, A352867.
%K A355702 nonn
%O A355702 1,2
%A A355702 _Scott R. Shannon_, Jul 14 2022