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

Author

N. J. A. Sloane, May 21 2004

Keywords

• nonn

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

Crossrefs

Cf. A090822, A091787, A091799, A091844.

Programs

Magma

[4] cat [(n^(n+1)+2*n-3)/(n-1): n in [2..20]]; // Vincenzo Librandi, Jul 16 2015

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 *)

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