A093149 a(1) = 4; a(n) = (n^(n+1)+2*n-3)/(n-1) for n > 1.

4, 9, 42, 343, 3908, 55989, 960802, 19173963, 435848052, 11111111113, 313842837674, 9726655034463, 328114698808276, 11966776581370173, 469172025408063618, 19676527011956855059, 878942778254232811940, 41660902667961039785745, 2088331858752553232964202

Offset

1,1

Comments

This sequence represents the first step in which the Gijswijt's sequence (A090822), with a minimum value of n-1, reaches the value n+1 for the first time. For example, the first '3' in A090822 is in step 9, the first '4' in A091787 is in step 42, the first '5' in A091799 is in step 343 and so on. - Sergio Pimentel, Jul 15 2015

Links

Table of n, a(n) for n=1..19.

Maple

A093149:=n->(n^(n+1)+2*n-3)/(n-1): (4, seq(A093149(n), n=2..30)); # Wesley Ivan Hurt, Jul 15 2015

Mathematica

{4}~Join~Table[(n^(n + 1) + 2 n - 3)/(n - 1), {n, 2, 19}] (* Michael De Vlieger, Jul 13 2015 *)

Prog

(PARI) main(size)=my(v=vector(size), i); v[1]=4; for(i=2, size, v[i]=(i^(i+1)+2*i-3)/(i-1)); v \\ Anders Hellström, Jul 13 2015
(Magma) [4] cat [(n^(n+1)+2*n-3)/(n-1): n in [2..20]]; // Vincenzo Librandi, Jul 16 2015

Crossrefs

Cf. A090822, A091787, A091799, A091844.

Sequence in context: A138544 A219287 A359922 * A048054 A284973 A239853

Adjacent sequences: A093146 A093147 A093148 * A093150 A093151 A093152

Keyword

nonn

Author

N. J. A. Sloane, May 21 2004

Status

approved