A284008 a(n) = lcm(A260443(n), A260443(1+n)).

2, 6, 6, 30, 90, 90, 30, 210, 630, 450, 1350, 1890, 3150, 3150, 210, 2310, 6930, 3150, 47250, 330750, 992250, 141750, 47250, 103950, 173250, 110250, 330750, 519750, 242550, 242550, 2310, 30030, 90090, 34650, 3638250, 3638250, 272868750, 173643750, 11576250, 200103750, 600311250, 34728750, 2604656250, 28651218750, 1910081250, 272868750, 3638250, 9459450, 15765750

Offset

0,1

Links

Antti Karttunen, Table of n, a(n) for n = 0..4096

Index entries for sequences related to lcm's

Formula

a(n) = lcm(A260443(n), A260443(1+n)).

a(n) = A277324(n) / A277198(n).

Other identities. For all n >= 0:

A001222(a(n)) = A284009(n).

Mathematica

a[p_?PrimeQ] := a[p] = Prime[ PrimePi[p] + 1]; a[1] = 1; a[n_] := a[n] = Times @@ ( a[First[#]] ^ Last[#] & ) /@ FactorInteger[n]; (* after Jean-François Alcover, in A003961 *) A[n_]:= If[n<2, n + 1, If[EvenQ[n], a[A[n/2]], A[(n - 1)/2] A[(n + 1)/2]]] ; Table[A[n], {n, 0, 51}] (* sequence A260443 *) Table[LCM[A[n], A[n + 1]], {n, 0, 101}] (* Indranil Ghosh, Mar 22 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))));
A284008(n) = lcm(A260443(n), A260443(1+n));
(Scheme)
(define (A284008 n) (lcm (A260443 n) (A260443 (+ 1 n))))
(define (A284008 n) (/ (A277324 n) (A277198 n)))

Crossrefs

Cf. A260443, A277198, A277324, A277330, A284009.

Sequence in context: A083907 A084343 A025552 * A284576 A060114 A033188

Adjacent sequences: A284005 A284006 A284007 * A284009 A284010 A284011

Keyword

nonn

Author

Antti Karttunen, Mar 22 2017

Status

approved