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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.
4
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
1,1
COMMENTS
See A186219 for a discussion of adjusted joint rank sequences.
EXAMPLE
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.
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 *)
CROSSREFS
Sequence in context: A087268 A106765 A190785 * A061979 A050748 A348638
KEYWORD
nonn
AUTHOR
Clark Kimberling, Feb 17 2011
STATUS
approved