A284374 - OEIS

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A284374

a(1) = a(2) = 1; a(n) is the largest prime <= (a(n-a(n-1)) + a(n-a(n-2))) for n > 2.

1, 1, 2, 3, 3, 3, 5, 5, 5, 5, 5, 7, 7, 7, 7, 7, 7, 7, 13, 11, 7, 11, 13, 11, 13, 13, 13, 13, 13, 13, 13, 23, 13, 11, 19, 19, 13, 23, 19, 13, 23, 23, 19, 19, 23, 23, 19, 23, 23, 23, 23, 23, 23, 23, 43, 19, 29, 31, 23, 23, 43, 31, 31, 23, 31, 37, 31, 23, 43, 31, 23, 43, 31

(list; graph; refs; listen; history; text; internal format)

OFFSET

1,3

LINKS

Altug Alkan, Table of n, a(n) for n = 1..10000

Altug Alkan, Alternative scatterplot of A284374

Altug Alkan, Alternative graph of A284374

FORMULA

a(1) = a(2) = 1; a(n) = A007917(a(n-a(n-1)) + a(n-a(n-2))) for n > 2.

EXAMPLE

a(4) = 3 because a(4 - a(3)) + a(4 - a(2)) = a(2) + a(3) = 1 + 2 = 3 and A007917(3) = 3.

MATHEMATICA