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A251842 Number of (n+2) X (5+2) 0..3 arrays with every 3 X 3 subblock row and column sum nonprime and every diagonal and antidiagonal sum prime. 1

%I #6 Jun 22 2022 01:49:29

%S 1443,2672,8582,18708,79817,277125,616922,2656032,9359217,20878370,

%T 90230406,320039166,713991464,3094337461,11011364659,24565215616,

%U 106623444574,380064039869,847869435282,3682986619320,13139491573372

%N Number of (n+2) X (5+2) 0..3 arrays with every 3 X 3 subblock row and column sum nonprime and every diagonal and antidiagonal sum prime.

%C Column 5 of A251845.

%H R. H. Hardin, <a href="/A251842/b251842.txt">Table of n, a(n) for n = 1..210</a>

%F Empirical: a(n) = 64*a(n-3) -1282*a(n-6) +10366*a(n-9) -44576*a(n-12) +120485*a(n-15) -214956*a(n-18) +245225*a(n-21) -170457*a(n-24) +68626*a(n-27) -15983*a(n-30) +2674*a(n-33) -185*a(n-36) for n>43.

%e Some solutions for n=4

%e ..1..0..0..1..0..0..1....0..1..0..0..1..0..0....0..1..0..3..1..0..0

%e ..1..0..3..1..0..0..1....0..1..0..0..1..0..0....1..2..1..1..2..1..1

%e ..2..1..1..2..1..1..2....1..2..1..1..2..1..1....0..1..3..0..1..0..0

%e ..1..0..0..1..0..3..1....3..1..0..0..1..3..0....3..1..0..0..1..0..3

%e ..1..3..0..1..0..0..1....0..1..3..0..1..0..0....3..2..1..1..2..1..1

%e ..2..1..1..2..1..1..2....1..2..1..1..2..1..1....0..1..0..0..1..3..0

%Y Cf. A251845.

%K nonn

%O 1,1

%A _R. H. Hardin_, Dec 09 2014

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Last modified June 17 00:36 EDT 2024. Contains 373432 sequences. (Running on oeis4.)