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A326232 Numbers n such that N = n^2 is a twin rank (cf. A002822: 6N +- 1 are twin primes). 8
1, 5, 10, 35, 60, 70, 75, 210, 240, 385, 430, 445, 495, 590, 655, 730, 805, 815, 835, 1005, 1040, 1045, 1230, 1390, 1430, 1530, 1670, 1715, 1850, 1890, 1920, 2000, 2020, 2100, 2110, 2245, 2310, 2405, 2415, 2495, 2545, 2685, 2755, 2840, 2935, 2950, 3045, 3255, 3260, 3335, 3420, 3650, 3775, 3805 (list; graph; refs; listen; history; text; internal format)
OFFSET

1,2

COMMENTS

Dinculescu notes that when n^2 > 1 is a twin rank (i.e., in A002822), then n is always a multiple of 5, and if n^3 > 1 is a twin rank, it is divisible by 7. See A326231 for the terms > 1 divided by 5.

See A326234 and A326233 for n^3, A326236 and A326235 for n^6.

LINKS

A. Dinculescu, Table of n, a(n) for n = 1..10001

A. Dinculescu, On the Numbers that Determine the Distribution of Twin Primes, Surveys in Mathematics and its Applications, 13 (2018), 171-181.

PROG

(PARI) select( is(n)=!for(s=1, 2, ispseudoprime(6*n^2+(-1)^s)||return), [1..5000])

CROSSREFS

Cf. A002822, A326231 (a(n)/5, n>1), A326233, A326234 (analog for n^3), A326235, A326236 (analog for n^6), A326230 (least twin rank m^n for given n).

Sequence in context: A121158 A214650 A032772 * A189732 A307607 A174933

Adjacent sequences:  A326229 A326230 A326231 * A326233 A326234 A326235

KEYWORD

nonn

AUTHOR

M. F. Hasler and Antonie Dinculescu, Jun 14 2019

STATUS

approved

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Last modified April 10 18:49 EDT 2021. Contains 342853 sequences. (Running on oeis4.)