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A294086
Numbers k such that k divides the number of planar partitions of k (A000219).
1
1, 3, 6, 8, 10, 281, 382, 590, 5135, 13897, 31387, 37045, 46199, 85057
OFFSET
1,2
COMMENTS
a(15) > 10^5. - Seiichi Manyama, Feb 11 2018
Next term, if it exists, is greater than 250000. - Vaclav Kotesovec, Mar 02 2018
LINKS
Eric Weisstein's World of Mathematics, Plane Partition
EXAMPLE
281 is in the sequence because A000219(281) = 126261896396707768167577329446424334 is divisible by 281.
MATHEMATICA
pp[0] = 1; pp[n_] := pp[n] = (1/n)*Sum[pp[n-k]*DivisorSigma[2, k], {k, 1, n}]; Reap[For[n = 0; k = 1, k < 10^5, k++, If[Divisible[pp[k], k], n++; Print["a(", n, ") = ", k, " pp(", k, ") = ", pp[k]]; Sow[k]]]][[2, 1]] (* Jean-François Alcover, Feb 11 2018 *)
CROSSREFS
KEYWORD
nonn,more
AUTHOR
Ilya Gutkovskiy, Feb 09 2018
EXTENSIONS
a(14) from Seiichi Manyama, Feb 11 2018
STATUS
approved