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A121626 Real part of (1 + n*i)^n, where i=sqrt(-1). 1
1, -3, -26, 161, 2876, -27755, -740536, 9722113, 343603216, -5707904499, -250756091552, 5039646554593, 264489160965056, -6237995487261915, -380574552503498624, 10303367499652761601, 716309568462681538816, -21891769059478538933603 (list; graph; refs; listen; history; text; internal format)
OFFSET

1,2

COMMENTS

This sequence is a companion to A115415: real part of (n + i)^n.

LINKS

Table of n, a(n) for n=1..18.

FORMULA

a(n) = (1/2) * ( (i+n)^n + (i-n)^n ) * i^(n*(2*n+1)). [Bruno Berselli, Jan 28 2014]

EXAMPLE

a(4) = 161 since (1 + 4i)^4 = (161 - 240i).

MATHEMATICA

f[n_] := Re[(1 + n*I)^n]; Array[f, 18] (* Robert G. Wilson v, Aug 17 2006 *)

Table[(1/2) ((I + n)^n + (I - n)^n) I^(n (2 n + 1)), {n, 20}] (* Bruno Berselli, Jan 28 2014 *)

CROSSREFS

Cf. A115415.

Sequence in context: A034493 A265467 A252872 * A038697 A226351 A091262

Adjacent sequences:  A121623 A121624 A121625 * A121627 A121628 A121629

KEYWORD

sign,easy

AUTHOR

Gary W. Adamson, Aug 12 2006

EXTENSIONS

More terms from Robert G. Wilson v, Aug 17 2006

STATUS

approved

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Last modified November 14 04:44 EST 2019. Contains 329108 sequences. (Running on oeis4.)