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A037040 Number of odd nonprimes < (2n+1)^2. 2
0, 1, 4, 10, 19, 31, 46, 65, 84, 109, 136, 166, 199, 236, 275, 319, 364, 413, 466, 521, 578, 642, 707, 776, 844, 923, 996, 1079, 1168, 1254, 1342, 1436, 1535, 1636, 1740, 1846, 1960, 2074, 2186, 2310, 2434, 2559, 2690, 2825, 2961, 3103, 3248, 3392, 3542 (list; graph; refs; listen; history; text; internal format)
OFFSET

0,3

REFERENCES

C. R. Christofferson, 15219 Wickmere, Houston, TX 77062, (281) 486-4139 (unpublished notes)

LINKS

Table of n, a(n) for n=0..48.

EXAMPLE

The odd nonprimes < 25 are 1,9,15,21, so a(2)=4.

CROSSREFS

A038377[ n ]-1.

Sequence in context: A022793 A005448 A301247 * A007077 A301202 A301021

Adjacent sequences:  A037037 A037038 A037039 * A037041 A037042 A037043

KEYWORD

nonn

AUTHOR

C.R.Christofferson (magpie56(AT)aol.com)

STATUS

approved

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Last modified April 10 08:09 EDT 2021. Contains 342845 sequences. (Running on oeis4.)