A081301 Subdiagonal of square array A081297.

1, 1, 13, 41, 991, 5461, 194713, 1545265, 73022131, 758924981, 44709567013, 575279386969, 40614439994311, 623479972408021, 51316625644764721, 915589327332039905, 86090052046429522747, 1750836276286883890741

Offset

0,3

Links

Vincenzo Librandi, Table of n, a(n) for n = 0..200

Formula

a(n) = ((n+2)^(n+1)-(-(n+1))^(n+1))/(2*n+3).

Mathematica

Table[((n + 2)^(n + 1) - (-(n + 1))^(n + 1)) / (2 n + 3), {n, 0, 20}] (* Vincenzo Librandi, Aug 08 2013 *)

Prog

(Magma) [((n+2)^(n+1)-(-(n+1))^(n+1))/(2*n+3):n in [0..20]]; // Vincenzo Librandi, Aug 08 2013

Crossrefs

Cf. A081298, A081299, A081300, A081302.

Sequence in context: A116153 A116209 A002673 * A159527 A139277 A162265

Adjacent sequences: A081298 A081299 A081300 * A081302 A081303 A081304

Keyword

easy,nonn

Author

Paul Barry, Mar 17 2003

Status

approved