cp's OEIS Frontend

A371096 Array A read by upward antidiagonals in which the entry A(n,k) in row n and column k is defined by A(1, k) = 8*k-7, and A(n+1, k) = A371094(A(n, k)), n,k >= 1.

%I A371096 #8 May 06 2024 17:48:25
%S A371096 1,21,9,5461,117,17,357913941,11605,213,25,1537228672809129301,
%T A371096 72701269,87381,309,33,28356863910078205288614550619314017621,
%U A371096 3752999689475413,91625968981,30037,405,41,9649340769776349618630915417390658987772498722136713669954798667326094136661,27043212804868893898596335048021,100743818301219097892181,760567125,79189,501,49
%N A371096 Array A read by upward antidiagonals in which the entry A(n,k) in row n and column k is defined by A(1, k) = 8*k-7, and A(n+1, k) = A371094(A(n, k)), n,k >= 1.
%e A371096 Array begins:
%e A371096 n\k|         1         2            3          4           5          6
%e A371096 ---+--------------------------------------------------------------------
%e A371096 1  |         1,        9,          17,        25,         33,        41,
%e A371096 2  |        21,      117,         213,       309,        405,       501,
%e A371096 3  |      5461,    11605,       87381,     30037,      79189,     48469,
%e A371096 4  | 357913941, 72701269, 91625968981, 760567125, 1968526677, 299193685,
%o A371096 (PARI)
%o A371096 up_to = 28;
%o A371096 A371094(n) = { my(m=1+3*n, e=valuation(m,2)); ((m*(2^e)) + (((4^e)-1)/3)); };
%o A371096 A371096sq(n,k) = if(1==n,8*k-7,A371094(A371096sq(n-1,k)));
%o A371096 A371096list(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] = A371096sq((a-(col-1)),col))); (v); };
%o A371096 v371096 = A371096list(up_to);
%o A371096 A371096(n) = v371096[n];
%Y A371096 Cf. A371094, A017077 (row 1).
%Y A371096 Every fourth column (1, 5, 9, 13, 17, ...) of array A372282.
%Y A371096 Cf. also arrays A257852, A371100 and A371102.
%K A371096 nonn,tabl,easy
%O A371096 1,2
%A A371096 _Antti Karttunen_, Apr 21 2024