A082189 Main diagonal of square array A082025.

1, 5, 12, 41, 26, 103, 58, 181, 92, 293, 128, 439, 174, 617, 230, 817, 290, 1037, 376, 1225, 446, 1565, 542, 1883, 628, 2227, 746, 2555, 848, 2983, 962, 3409, 1102, 3859, 1238, 4331, 1384, 4823, 1532, 5345, 1684, 5945, 1858, 6539, 2038, 7135, 2218, 7801

Offset

1,2

Links

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

Maple

b:= proc(t) false end: b(1):= true: ncpr:= proc() local i, m; m:= args[1]; for i from 2 to nargs do if igcd (m, args[i])<>1 then return true fi od; false end: T:= proc(n, k) option remember; local h, t, l; if n<1 or k<1 or n=1 and k=1 then t:=1 else h:= 1- 2* irem(n+k, 2); l:= T(n-1, k), T(n, k-1), T(n-1, k-1), T(n+h, k-h); for t while b(t) or ncpr(t, l) do od fi; b(t):= true; t end: seq (T(n, n), n=1..40); # Alois P. Heinz, Oct 07 2009

Mathematica

b[_] = False; b[1] = True;
ncpr[args_] := Module[{i, m}, m = args[[1]]; For[i = 2, i <= Length[args], i++, If[GCD[m, args[[i]]] != 1, Return[True]]]];
T[n_, k_] := T[n, k] = Module[{h, t, l}, If[n < 1 || k < 1 || n == 1 && k == 1, t = 1, h = 1 - 2*Mod[n + k, 2]; l = {T[n - 1, k], T[n, k - 1], T[n - 1, k - 1], T[n + h, k - h]}; For[t = 1, b[t] || ncpr[Join[{t}, l]], t++]; b[t] = True; t]];
Table [T[n, n], {n, 1, 40}] (* Jean-François Alcover, Jun 03 2018, after Alois P. Heinz *)

Crossrefs

Cf. A082025, A082187, A082188, A082190.

Sequence in context: A092772 A164737 A120779 * A129795 A187916 A052644

Adjacent sequences: A082186 A082187 A082188 * A082190 A082191 A082192

Keyword

nonn

Author

Amarnath Murthy, Apr 07 2003

Extensions

Edited and more terms from Alois P. Heinz, Oct 07 2009

Status

approved