A186290 Adjusted joint rank sequence of (f(i)) and (g(j)) with f(i) after g(j) when f(i)=g(j), where f and g are the squares and pentagonal numbers. Complement of A186291.
2, 3, 5, 7, 9, 11, 12, 14, 16, 18, 20, 21, 23, 25, 27, 29, 31, 32, 34, 36, 38, 40, 41, 43, 45, 47, 49, 51, 52, 54, 56, 58, 60, 61, 63, 65, 67, 69, 71, 72, 74, 76, 78, 80, 81, 83, 85, 87, 89, 90, 92, 94, 96, 98, 100, 101, 103, 105, 107, 109, 110, 112, 114, 116, 118, 120, 121, 123, 125, 127, 129, 130, 132, 134, 136, 138, 140, 141, 143, 145, 147, 149, 150, 152, 154, 156, 158, 160, 161, 163, 165, 167, 169, 170, 172, 174, 176, 178, 180, 181
Offset: 1
Keywords
Examples
First, write 1..4...9....16....25..36..49..... (squares) 1....5...12....22....35......51.. (pentagonal) Replace each number by its rank, where ties are settled by ranking the square number after the pentagonal: a=(2,3,5,7,9,11,12,14,....)=A186290. b=(1,4,6,8,10,13,15,17,...)=A186291.
Programs
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Mathematica
(* adjusted joint ranking; general formula *) d=-1/2; u=1; v=0; w=0; x=3/2; y=-1/2; z=0; h[n_]:=-y+(4x(u*n^2+v*n+w-z-d)+y^2)^(1/2); a[n_]:=n+Floor[h[n]/(2x)]; k[n_]:=-v+(4u(x*n^2+y*n+z-w+d)+v^2)^(1/2); b[n_]:=n+Floor[k[n]/(2u)]; Table[a[n], {n, 1, 100}] (* A186290 *) Table[b[n], {n, 1, 100}] (* A186291 *)
Comments