A162556 Numbers k which are concatenations k=x//y such that x^2 + y^2 - x*y = k.

37, 48, 111, 147, 148, 525, 832, 1036, 1443, 2457, 3367, 3468, 4477, 5887, 6591, 6993, 7696, 11011, 12025, 12096, 12432, 12493, 12636, 12691, 12943, 12987, 13357, 13377, 13467, 13468, 333667, 334668

Offset

1,1

Links

Table of n, a(n) for n=1..32.

Example

147 is a term because 147 = 14//7 = 14^2 + 7^2 - 14*7.

Maple

Lton := proc(L) add( op(i, L)*10^(i-1), i=1..nops(L)) ; end:
for n from 10 do dgs := convert(n, base, 10) ; for spli from 1 to nops(dgs)-1 do ydgs := [op(1..spli, dgs)] ; xdgs := [op(spli+1..nops(dgs), dgs)] ; if op(-1, ydgs) <> 0 then x := Lton(xdgs) ; y := Lton(ydgs) ; if y^2+x^2-x*y = n then print(n) ; fi; fi; od: od: # R. J. Mathar, Jul 16 2009

Crossrefs

Sequence in context: A218834 A039465 A083240 * A129072 A297911 A253019

Adjacent sequences: A162553 A162554 A162555 * A162557 A162558 A162559

Keyword

nonn,base

Author

Claudio Meller, Jul 06 2009

Extensions

Definition simplified and 37, 48, 333667, 334668 added by R. J. Mathar, Jul 16 2009

Status

approved