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A372560 Array read by upward antidiagonals: A(n, k) = A371094(A(n-1, k)) for n > 1, k >= 1; A(1, k) = A372443(k-1).

%I A372560 #4 May 10 2024 11:00:12
%S A372560 27,165,41,8021,501,31,12408149,48469,189,47,19607957362005,299193685,
%T A372560 4565,285,71,32439509492992549521282389,7552911875069269,1758549,6869,
%U A372560 429,107,58947232705679751034215288252890081792789279233365,3195535888075328282939605996885,173230347605,2643285,10325,645,161
%N A372560 Array read by upward antidiagonals: A(n, k) = A371094(A(n-1, k)) for n > 1, k >= 1; A(1, k) = A372443(k-1).
%e A372560 Array begins:
%e A372560 n\k|        1          2        3        4        5         6           7
%e A372560 ---+-----------------------------------------------------------------------
%e A372560 1  |       27,        41,      31,      47,      71,      107,        161,
%e A372560 2  |      165,       501,     189,     285,     429,      645,       1941,
%e A372560 3  |     8021,     48469,    4565,    6869,   10325,    31061,     374101,
%e A372560 4  | 12408149, 299193685, 1758549, 2643285, 7951701, 95769941, 9216283989,
%o A372560 (PARI)
%o A372560 up_to = 28;
%o A372560 A000265(n) = (n>>valuation(n,2));
%o A372560 A372443(n) = { my(x=27); while(n, x=A000265(3*x+1); n--); (x); };
%o A372560 A371094(n) = { my(m=1+3*n, e=valuation(m,2)); ((m*(2^e)) + (((4^e)-1)/3)); };
%o A372560 A372560sq(n,k) = if(1==n,A372443(k-1),A371094(A372560sq(n-1,k)));
%o A372560 A372560list(up_to) = { my(v = vector(up_to), i=0); for(a=1,oo, for(col=1,a, i++; if(i > up_to, return(v)); v[i] = A372560sq((a-(col-1)),col))); (v); };
%o A372560 v372560 = A372560list(up_to);
%o A372560 A372560(n) = v372560[n];
%Y A372560 Cf. A371094, A372282, A372443 (the top row), A372444 (the leftmost column), A372561.
%K A372560 nonn,tabl
%O A372560 1,1
%A A372560 _Antti Karttunen_, May 08 2024