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A053018 Let Do(n)=A006566(n)=n-th dodecahedral number. Consider all integer triples (i,j,k), j >= k>0, with Do(i)=Do(j)+Do(k), ordered by increasing i; sequence gives j values. 3
178, 150, 2012, 4840, 7773, 8904, 17403, 22363, 24699, 26200, 21916, 22250, 37022, 39223, 61190, 62899, 102450, 123108, 223132, 269966, 374384, 591930, 554636, 636031, 743699, 892780, 1295888, 1468290, 1395491, 1822152, 1859152, 1957822 (list; graph; refs; listen; history; text; internal format)
OFFSET

1,1

COMMENTS

i values are A053017 and k values are A053019.

LINKS

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

EXAMPLE

Do(179) = 25665020 = 25236484 + 428536 = Do(178) + Do(46);

Do(184) = 27880600 = 15086400 + 12794200 = Do(150) + Do(142).

MATHEMATICA

(* This is just a recomputation of j values, given i values. *) A053017 = {179, 184, 2014, 4891, 8877, 8907, 17650, 24248, 25216, 26204, 27156, 27570, 37555, 40052, 61195, 68747, 109707, 123114, 223139, 270776, 374392, 591939, 604344, 670751, 836587, 892790, 1295899, 1479632, 1664436, 1822164, 1966614, 1981707} ; do[n_] := n*(3*n-1)*(3*n-2)/2; k0[i_, j_] := k /. FindRoot[do[i] == do[j] + do[k], {k, j/2}][[1]] // Quiet; sols = Reap[Do[i = A053017[[m]]; doi = do[i]; Print["i = ", i]; Do[k1 = Floor[k0[i, j]]; k2 = k1+1; If[k1 <= j, If[doi == do[j] + do[k1], Print[ijk = {i, j, k1}]; Sow[ijk]; Break[], If[doi == do[j] + do[k2], Print[ijk = {i, j, k2}]; Sow[ijk]; Break[]]]], {j, i-1, 1, -1}], {m, 1, Length[A053017]}]][[2, 1]]; A053018 = sols[[All, 2]] (* Jean-Fran├žois Alcover, Feb 17 2015 *)

CROSSREFS

Sequence in context: A189910 A189904 A189160 * A046436 A114081 A217037

Adjacent sequences:  A053015 A053016 A053017 * A053019 A053020 A053021

KEYWORD

nice,nonn

AUTHOR

Klaus Strassburger (strass(AT)ddfi.uni-duesseldorf.de), Feb 24 2000

EXTENSIONS

More terms from Jon E. Schoenfield, Aug 13 2007

a(27)-a(32) from Donovan Johnson, Aug 15 2010

STATUS

approved

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Last modified August 3 19:54 EDT 2021. Contains 346441 sequences. (Running on oeis4.)