OFFSET
1,1
COMMENTS
This is the case a=2 of Theorem 1 in the paper of Hamahata and Kokubun (see Links section).
Named after the Italian mathematician Michele Cipolla (1880-1947). - Amiram Eldar, Jun 15 2021
LINKS
Bruno Berselli, Table of n, a(n) for n = 1..50
Umberto Cerruti, Pseudoprimi di Fermat e numeri di Carmichael (in Italian), 2013. The sequence is on page 3.
Michele Cipolla, Sui numeri composti P, che verificano la congruenza di Fermat a^(P-1) = 1 (mod P), Annali di Matematica, Vol. 9 (1904), pp. 139-160.
Y. Hamahata and Y. Kokubun, Cipolla Pseudoprimes, Journal of Integer Sequences, Vol. 10 (2007), Article 07.8.6.
MAPLE
P:=proc(q)local n;
for n from 3 to q do print((4^ithprime(n)-1)/3);
od; end: P(100); # Paolo P. Lava, Oct 11 2013
MATHEMATICA
(4^# - 1)/3 & /@ Prime[Range[3, 15]]
PROG
(Magma) [(4^NthPrime(n)-1)/3: n in [3..15]];
(Maxima)
Prime(n) := block(if n = 1 then return(2), return(next_prime(Prime(n-1))))$
makelist((4^Prime(n)-1)/3, n, 3, 15);
(Haskell)
a210454 = (`div` 3) . (subtract 1) . (4 ^) . a000040 . (+ 2)
-- Reinhard Zumkeller, Jan 22 2013
(PARI) a(n)=4^prime(n+2)\3 \\ Charles R Greathouse IV, Jul 09 2015
CROSSREFS
KEYWORD
nonn
AUTHOR
Bruno Berselli, Jan 21 2013 - proposed by Umberto Cerruti (Department of Mathematics "Giuseppe Peano", University of Turin, Italy)
STATUS
approved