OFFSET
0,1
COMMENTS
See A183175 = {1, 2, 17, 79, 118, 162, 177, ...} for the indices of primes.
LINKS
Brady Haran and Simon Pampena, Glitch Primes and Cyclops Numbers, Numberphile video (2015).
Patrick De Geest, Palindromic Wing Primes: (3)5(3), updated: June 25, 2017.
Makoto Kamada, Factorization of 33...33533...33, updated Dec 11 2018.
Index entries for linear recurrences with constant coefficients, signature (111,-1110,1000).
FORMULA
G.f.: (5 - 202*x - 100*x^2)/((1 - x)(1 - 10*x)(1 - 100*x)).
a(n) = 111*a(n-1) - 1110*a(n-2) + 1000*a(n-3) for n > 2.
E.g.f.: exp(x)*(10*exp(99*x) + 6*exp(9*x) - 1)/3. - Stefano Spezia, Sep 24 2024
MAPLE
A332135 := n -> (10^(2*n+1)-1)/3+2*10^n;
MATHEMATICA
Array[ (10^(2 # + 1)-1)/3 + 2*10^# &, 15, 0]
PROG
CROSSREFS
KEYWORD
nonn,base,easy
AUTHOR
M. F. Hasler, Feb 09 2020
STATUS
approved