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 A269729 a(n) = row number of extended Wythoff array (see A035513) which contains the sequence obtained by reading the n-th row backwards (and adjusting signs). 3
 0, 1, 2, 3, 4, 7, 10, 5, 8, 11, 6, 9, 12, 20, 28, 15, 23, 31, 18, 26, 13, 21, 29, 16, 24, 32, 19, 27, 14, 22, 30, 17, 25, 33, 54, 75, 41, 62, 83, 49, 70, 36, 57, 78, 44, 65, 86, 52, 73, 39, 60, 81, 47, 68, 34, 55, 76, 42, 63, 84, 50, 71, 37, 58, 79, 45, 66, 87, 53, 74, 40 (list; graph; refs; listen; history; text; internal format)
 OFFSET 0,3 COMMENTS Conjecture: sequence is its own inverse. - R. J. Mathar, May 08 2019 REFERENCES J. H. Conway, Postings to Math Fun Mailing List, Nov 25 1996 and Dec 02 1996. LINKS J. H. Conway, Allan Wechsler, Marc LeBrun, Dan Hoey, N. J. A. Sloane, On Kimberling Sums and Para-Fibonacci Sequences, Correspondence and Postings to Math-Fun Mailing List, Nov 1996 to Jan 1997 EXAMPLE Take n=5: reading row 5 of A035513 backwards gives ... 23, 14, 9, 5, 4, 1, 3, -2, 5, -7, 12, -19, ..., which after adjusting the signs is row 7, so a(5) = 7. MAPLE A035513 := proc(r::integer, c::integer)     option remember;     if c = 1 then         A003622(r) ;     elif c > 1 then         A022342(1+procname(r, c-1)) ;     elif c < 1 then         procname(r, c+2)-procname(r, c+1) ;     end if; end proc: # search in A035513 for row with consecutive w1, w2 A035513inv := proc(w1::integer, w2::integer)     local r, c, W1, W2 ;     for r from 1 do         if A035513(r, 1) > w2 then             return -1 ;         end if;         for c from 1 do             W1 := A035513(r, c) ;             W2 := A035513(r, c+1) ;             if W1=w1 and W2=w2 then                 return r-1 ;             elif W2 > w2 then                 break;             end if;         end do:     end do: end proc: A269729 := proc(n)     option remember;     local c, W1, W2, r, n35513;     n35513 := n+1 ;     for c from 1 by -1 do         W1 := A035513(n35513, c) ;         W2 := A035513(n35513, c-1) ;         if W1 < 0 and abs(W2) > abs(W1) then             r :=  A035513inv(abs(W1), abs(W2)) ;             if r >= 0 then                 return r;             end if;         end if;     end do: end proc: seq(A269729(n), n=0..120) ; # R. J. Mathar, May 08 2019 CROSSREFS Cf. A000045, A022413-A022423, A035513, A269725, A269726, A269729. See A269733 for first differences. Sequence in context: A078696 A256772 A274976 * A098115 A182833 A182832 Adjacent sequences:  A269726 A269727 A269728 * A269730 A269731 A269732 KEYWORD nonn,easy AUTHOR N. J. A. Sloane, Mar 08 2016 EXTENSIONS Terms from a(18) on by R. J. Mathar, May 08 2019 STATUS approved

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Last modified September 24 03:26 EDT 2021. Contains 347623 sequences. (Running on oeis4.)