A283484 Odd bisection of A283983; square root of the largest square dividing A277324.

1, 1, 3, 1, 3, 3, 15, 1, 3, 15, 45, 15, 15, 15, 105, 1, 3, 105, 225, 525, 1575, 1125, 1575, 105, 105, 525, 1575, 525, 105, 105, 1155, 1, 3, 1155, 1575, 3675, 7875, 275625, 55125, 5775, 17325, 275625, 4134375, 55125, 55125, 275625, 121275, 1155, 1155, 40425, 385875, 202125, 606375, 1929375, 606375, 5775, 8085, 40425, 121275, 40425, 1155, 1155, 15015, 1, 3

Offset

0,3

Links

Antti Karttunen, Table of n, a(n) for n = 0..2048

Formula

a(n) = A283983((2*n)+1).

a(n) = A000188(A277324(n)).

A001222(a(n)) = A284265(n).

Mathematica

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]]]; A275812[n_]:= PrimeOmega[n] - If[n<2, 0, Count[Transpose[FactorInteger[n]][[2]], 1]]; A277324[n_]:=A260443[2n + 1];  A000188[n_]:=  Sum[Boole[Mod[i^2, n] == 0], {i, n}]; Table[A000188[A277324[n]], {n, 0, 50}] (* Indranil Ghosh, Mar 28 2017 *)

Prog

(PARI)
A003961(n) = my(f = factor(n)); for (i=1, #f~, f[i, 1] = nextprime(f[i, 1]+1)); factorback(f); \\ From Michel Marcus
A260443(n) = if(n<2, n+1, if(n%2, A260443(n\2)*A260443(n\2+1),  A003961(A260443(n\2)))); \\ Cf. Charles R Greathouse IV's code for "ps" in A186891 and A277013.
A277324(n) = A260443((2*n)+1);
A000188(n) = core(n, 1)[2]; \\ This function from Michel Marcus, Feb 27 2013
A283484(n) = A000188(A277324(n));
(Scheme)
(define (A283484 n) (A000188 (A277324 n)))
(define (A283484 n) (A283983 (+ n n 1)))

Crossrefs

Cf. A000188, A001222, A277324, A283983, A284265.

Sequence in context: A238313 A163270 A098743 * A355567 A130560 A088105

Adjacent sequences: A283481 A283482 A283483 * A283485 A283486 A283487

Keyword

nonn

Author

Antti Karttunen, Mar 25 2017

Status

approved