A121806 - OEIS

A121806

a(n) = f(prime(n*2+1) mod 3, prime(n*2+2) mod 3) where f(1,1) = 3, f(1,2) = 1, f(2,1) = 2, f(2,2) = 4.

2, 2, 2, 4, 3, 2, 4, 2, 1, 3, 4, 1, 1, 1, 1, 2, 2, 3, 4, 2, 2, 2, 3, 2, 4, 1, 4, 2, 1, 1, 1, 1, 3, 2, 4, 3, 1, 2, 2, 2, 2, 1, 2, 2, 4, 1, 1, 4, 3, 1, 4, 3, 4, 2, 3, 2, 1, 1, 4, 3, 4, 1, 1, 3, 1, 3, 2, 2, 4, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 4, 1, 4, 3, 1, 2, 2, 1, 1, 3, 1, 1, 4, 3, 1, 1, 1, 4, 3, 4, 2

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

OFFSET

1,1

LINKS

Table of n, a(n) for n=1..100.

FORMULA

a(n) = f(prime(n*2+1) mod 3, prime(n*2+2) mod 3) where f(1,1) = 3, f(1,2) = 1, f(2,1) = 2, f(2,2) = 4. - Jason Yuen, Sep 15 2024

MATHEMATICA

a = Partition[Table[1 + Mod[Prime[n], 3], {n, 3, 203}], 2] /. {2, 3} -> 1 /. {3, 2} -> 2 /. { 2, 2} -> 3 /. {3, 3} -> 4

PROG

(PARI) a(n) = my(f(i, j)=[3, 1, 2, 4][i*2+j-2]); f(prime(n*2+1)%3, prime(n*2+2)%3) \\ Jason Yuen, Sep 15 2024

CROSSREFS