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 A053012 Platonic numbers: a(n) is a tetrahedral (A000292), cube (A000578), octahedral (A005900), dodecahedral (A006566) or icosahedral (A006564) number. 11
 1, 4, 6, 8, 10, 12, 19, 20, 27, 35, 44, 48, 56, 64, 84, 85, 120, 124, 125, 146, 165, 216, 220, 231, 255, 286, 343, 344, 364, 455, 456, 489, 512, 560, 670, 680, 729, 742, 816, 891, 969, 1000, 1128, 1140, 1156, 1330, 1331, 1469, 1540, 1629, 1728, 1771, 1834 (list; graph; refs; listen; history; text; internal format)
 OFFSET 1,2 COMMENTS 19, the 3rd octahedral number, is the only prime platonic number. - Jean-François Alcover, Oct 11 2012 LINKS T. D. Noe, Table of n, a(n) for n = 1..1000 OEIS Wiki, Platonic numbers MATHEMATICA nn = 25; t1 = Table[n (n + 1) (n + 2)/6, {n, nn}]; t2 = Table[n^3, {n, nn}]; t3 = Table[(2*n^3 + n)/3, {n, nn}]; t4 = Table[n (3*n - 1) (3*n - 2)/2, {n, nn}]; t5 = Table[n (5*n^2 - 5*n + 2)/2, {n, nn}]; Select[Union[t1, t2, t3, t4, t5], # <= t1[[-1]] &] (* T. D. Noe, Oct 13 2012 *) PROG (Haskell) a053012 n = a053012_list !! (n-1) a053012_list = tail \$ f    [a000292_list, a000578_list, a005900_list, a006566_list, a006564_list]    where f pss = m : f (map (dropWhile (<= m)) pss)                  where m = minimum (map head pss) -- Reinhard Zumkeller, Jun 17 2013 (PARI) listpoly(lim, poly[..])=my(v=List()); for(i=1, #poly, my(P=poly[i], x=variable(P), f=k->subst(P, x, k), n, t); while((t=f(n++))<=lim, listput(v, t))); Set(v) list(lim)=my(n='n); listpoly(lim, n*(n+1)*(n+2)/6, n^3, (2*n^3+n)/3, n*(3*n-1)*(3*n-2)/2, n*(5*n^2-5*n+2)/2) \\ Charles R Greathouse IV, Oct 11 2016 CROSSREFS Numbers of partitions into Platonic numbers: A226748, A226749. Sequence in context: A307542 A225510 A131694 * A096160 A181055 A225506 Adjacent sequences:  A053009 A053010 A053011 * A053013 A053014 A053015 KEYWORD easy,nice,nonn AUTHOR Klaus Strassburger (strass(AT)ddfi.uni-duesseldorf.de), Feb 22 2000 STATUS approved

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Last modified April 15 23:59 EDT 2021. Contains 343019 sequences. (Running on oeis4.)