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A111649 a(n) = A001541(n)*A001653(n) + A001541(n)*A002315(n) + A001653(n)*A002315(n). 2
3, 71, 2379, 80763, 2744211, 93222359, 3166815963, 107578520351, 3654502875939, 124145519261543, 4217293152016491, 143263821649299119, 4866752642924153523, 165326326037771920631, 5616228332641321147899 (list; graph; refs; listen; history; text; internal format)
OFFSET

0,1

LINKS

Table of n, a(n) for n=0..14.

FORMULA

a(n) = A001653(2n+1)-2*A002315(n)^2, e.g. 2379=5741-2*41^2;

a(n) = A001652(2n)+A002315(n)^2+2, e.g. 2379=696+41^2+2;

a(n) = 2*A046176(n+1)+1, e.g. 2379=2*1189+1.

Empirical g.f.: -(20*x^6-700*x^5+700*x^4-20*x^3-x^2-34*x+3) / ((x-1)*(x^2-34*x+1)). - Colin Barker, Dec 14 2014

EXAMPLE

a(1) = 71 = 3*5+3*7+5*7.

CROSSREFS

Cf. A111647, A111648.

Sequence in context: A166449 A094458 A183548 * A349072 A272657 A226709

Adjacent sequences:  A111646 A111647 A111648 * A111650 A111651 A111652

KEYWORD

nonn

AUTHOR

Charlie Marion, Aug 24 2005

STATUS

approved

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Last modified May 26 17:16 EDT 2022. Contains 354092 sequences. (Running on oeis4.)