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A078203
Numbers k such that A004154(k) + 1 is prime.
4
1, 2, 3, 5, 6, 14, 15, 24, 74, 191, 222, 276, 2200, 3041, 3701, 4324, 6201
OFFSET
1,2
MATHEMATICA
f[n_] := n!/10^Sum[ Floor[n/5^k], {k, 1, Log[10, n] + 1}]; Do[ If[ PrimeQ[ f[n] + 1], Print[n]], {n, 1, 850}]
CROSSREFS
KEYWORD
nonn,base,more
AUTHOR
Cino Hilliard, Dec 23 2002
EXTENSIONS
Extended by Joshua Zucker, Robert G. Wilson v and Jason Earls, Dec 24 2002
a(13) from Don Reble, Jan 12 2006
a(14)-a(17) from Michael S. Branicky, Jul 23 2023
STATUS
approved