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A165938 a(n) = A002203(n^2) for n>=1. 4
2, 34, 2786, 1331714, 3710155682, 60245508192802, 5701755387019728962, 3145168096065837266706434, 10111847525912679844192131854786, 189482250299273866835746159841800035874, 20694642381734231604510939638726181796865594402 (list; graph; refs; listen; history; text; internal format)
OFFSET

1,1

LINKS

Paul D. Hanna, Table of n, a(n) for n = 1..40

FORMULA

a(n) == 2 (mod 32).

a(n) = (1+sqrt(2))^(n^2) + (1-sqrt(2))^(n^2).

Logarithmic derivative of A165937.

MATHEMATICA

Simplify[Table[(1 + Sqrt[2])^(n^2) + (1 - Sqrt[2])^(n^2), {n, 1, 7}]] (* G. C. Greubel, Apr 18 2016 *)

PROG

(PARI) {a(n)=polcoeff(2*(1-x)/(1-2*x-x^2 +x*O(x^(n^2))), n^2)}

CROSSREFS

Cf. A165937, A002203, A000129 (Pell numbers).

Sequence in context: A198909 A207865 A216082 * A255434 A206501 A183414

Adjacent sequences:  A165935 A165936 A165937 * A165939 A165940 A165941

KEYWORD

nonn

AUTHOR

Paul D. Hanna, Oct 18 2009

STATUS

approved

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Last modified December 7 05:14 EST 2019. Contains 329839 sequences. (Running on oeis4.)