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A283989
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Largest square dividing prime factorization representation of the n-th Stern polynomial: a(n) = A008833(A260443(n)).
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3
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1, 1, 1, 1, 1, 9, 1, 1, 1, 9, 25, 9, 1, 225, 1, 1, 1, 9, 25, 225, 49, 2025, 25, 225, 1, 225, 1225, 225, 1, 11025, 1, 1, 1, 9, 25, 11025, 49, 50625, 1225, 275625, 121, 2480625, 30625, 1265625, 49, 2480625, 1225, 11025, 1, 11025, 1225, 275625, 5929, 2480625, 1225, 275625
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OFFSET
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0,6
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LINKS
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FORMULA
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MATHEMATICA
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A003961[p_?PrimeQ] := A003961[p] = Prime[ PrimePi[p] + 1]; A003961[1] = 1; A003961[n_] := A003961[n] = Times @@ ( A003961[First[#]] ^ Last[#] & ) /@ FactorInteger[n] (* after Jean-François Alcover, Dec 01 2011 *); A260443[n_]:= If[n<2, n + 1, If[EvenQ[n], A003961[A260443[n/2]], A260443[(n - 1)/2] * A260443[(n + 1)/2]]]; A000188[n_]:= Sum[Boole[Mod[i^2, n] == 0], {i, n}]; Table[A000188[A260443[n]]^2, {n, 0, 20}] (* Indranil Ghosh, Mar 28 2017 *)
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PROG
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(PARI)
A003961(n) = my(f = factor(n)); for (i=1, #f~, f[i, 1] = nextprime(f[i, 1]+1)); factorback(f); \\ From Michel Marcus
(Scheme)
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CROSSREFS
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KEYWORD
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nonn
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AUTHOR
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STATUS
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approved
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