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 A136402 Prime Wedderburn-Etherington numbers. 0
 2, 3, 11, 23, 983, 2179, 24631, 3626149, 253450711, 596572387, 4958179972866730572551, 17950473826186485808766524097, 17690812163571687513245304152178763697755384812733, 9852801774222802457119814738073136914072348071335480633169417277909155746150705781482843 (list; graph; refs; listen; history; text; internal format)
 OFFSET 1,1 COMMENTS Corresponding indices are 4, 5, 7, 8, 13, 14, 17, 23, 28, 29, 63, 80, 134, 233, 534, 732, 1963, 3896, 7792, 7987, 8312, ... with no more up to 2*10^4. - Charles R Greathouse IV, Mar 23 2014 Next index which produces a prime is 48979. - Robert G. Wilson v, May 21 2014 LINKS MATHEMATICA a[n_?OddQ] := a[n] = Sum[a[k]*a[n - k], {k, 1, (n - 1)/2}]; a[n_?EvenQ] := a[n] = Sum[a[k]*a[n - k], {k, 1, n/2 - 1}] + (1/2)*a[n/2]*(1 + a[n/2]); a[0] = 0; a[1] = 1; Select[a@# & /@ Range@ 300, PrimeQ@# &] (* Robert G. Wilson v, May 20 2014, after Jean-François Alcover in A001190 *) CROSSREFS Cf. A001190. Sequence in context: A292817 A292112 A065849 * A137811 A041955 A239445 Adjacent sequences:  A136399 A136400 A136401 * A136403 A136404 A136405 KEYWORD nonn AUTHOR Charles R Greathouse IV, Mar 30 2008 STATUS approved

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Last modified May 20 09:27 EDT 2022. Contains 353871 sequences. (Running on oeis4.)