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A215015 Number of sphenic twins up to 10^n. 1
0, 0, 11, 337, 4206, 43330, 417479 (list; graph; refs; listen; history; text; internal format)
OFFSET

1,3

COMMENTS

The sphenic twin pairs {230, 231}, {285, 286}, ... are counted once at a time.

LINKS

Table of n, a(n) for n=1..7.

CROSSREFS

Cf. A007304, A215217, A066509, A215218, A215152.

Sequence in context: A086923 A206532 A106717 * A219072 A280669 A195505

Adjacent sequences:  A215012 A215013 A215014 * A215016 A215017 A215018

KEYWORD

nonn

AUTHOR

Martin Renner, Aug 06 2012

STATUS

approved

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Last modified March 19 15:02 EDT 2019. Contains 321330 sequences. (Running on oeis4.)