A186495 Adjusted joint rank sequence of (f(i)) and (g(j)) with f(i) after g(j) when f(i)=g(j), where f(i)=5i (A008587) and g(j)=j-th pentagonal number (A000326). Complement of A186496.
3, 4, 6, 7, 9, 10, 12, 13, 14, 15, 17, 18, 19, 21, 22, 23, 24, 25, 27, 28, 29, 30, 31, 33, 34, 35, 36, 37, 39, 40, 41, 42, 43, 44, 45, 47, 48, 49, 50, 51, 52, 54, 55, 56, 57, 58, 59, 60, 61, 63, 64, 65, 66, 67, 68, 69, 70, 72, 73, 74, 75, 76, 77, 78, 79, 81, 82, 83, 84, 85, 86, 87, 88, 89, 90, 92, 93, 94, 95, 96, 97, 98, 99, 100, 102, 103, 104, 105, 106, 107, 108, 109, 110, 111, 112, 114, 115, 116, 117, 118, 119, 120, 121, 122, 123, 124, 126, 127, 128, 129, 130, 131, 132, 133, 134, 135, 136, 138, 139, 140
Offset: 1
Keywords
Examples
First, write ...5..10..15..20..25..30..35..40... (5i), 1..5......12......22............35..(pentagonal numbers). Then replace each number by its rank, where ties are settled by ranking 5i after the pentagonal number: a=(3,4,6,7,9,10,12,13,14,15,17,...)=A186495, b=(1,2,5,8,11,16,20,26,32,38,46,..)=A186496.
Programs
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Mathematica
(* Adjusted joint rank sequences a and b, using general formula for ranking 1st degree u*n+v and 2nd degree x*n^2+y*n+z. *) d=-1/2; u=5; v=0; x=3/2; y=-1/2; h[n_]:=(-y+(4x(u*n+v-d)+y^2)^(1/2))/(2x); a[n_]:=n+Floor[h[n]]; k[n_]:=(x*n^2+y*n-v+d)/u; b[n_]:=n+Floor[k[n]]; Table[a[n],{n,1,120}] (* A186495 *) Table[b[n],{n,1,100}] (* A186496 *)