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A074487 a(1)=1, then "jump over next square": a(n) = 2*(a(n-1)+1)^2-a(n-1). 1
1, 7, 121, 29647, 1757978161, 6180974434379818327, 76408889916913830205838054898189612841, 11676636916670111980512852400247542904848802859324947344926081051625513021087 (list; graph; refs; listen; history; text; internal format)
OFFSET

1,2

COMMENTS

The rule "jump over next something" can be varied, see A075694, A075695.

LINKS

Table of n, a(n) for n=1..8.

FORMULA

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

EXAMPLE

a(1)=1; next square is (a(1)+1)^2=4; "jump over" it: 4+(4-1)=7; a(2)=7; next square is (a(2)+1)^2=64; "jump over" it: 64+(64-7)=121.

MAPLE

a(1) := 1; a(n) := 2*(a(n-1)+1)^2-a(n-1);

CROSSREFS

Cf. A075694, A075695.

Sequence in context: A211103 A012103 A012086 * A192566 A322090 A304420

Adjacent sequences:  A074484 A074485 A074486 * A074488 A074489 A074490

KEYWORD

easy,nonn

AUTHOR

Zak Seidov, Sep 26 2002

STATUS

approved

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Last modified May 21 00:36 EDT 2022. Contains 353886 sequences. (Running on oeis4.)