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A258483 Numbers n such that partial sums of the n-th row of the Pascal triangle (A007318) are all nonprime. 1
0, 9, 29, 33, 34, 37, 38, 39, 41, 45, 49, 65, 67, 69, 73, 74, 77, 85, 86, 92, 97, 98, 101, 105, 113, 114, 115, 117, 118, 121, 129, 133, 134, 137, 139, 141, 145, 146, 151, 154, 155, 158, 160, 161, 164, 165, 170, 173, 177, 182, 185, 186, 193, 194, 195, 199, 202, 205, 206, 209, 213, 214, 225, 227, 229, 230, 234, 241, 247, 257, 258, 259, 261, 263, 265, 266, 269, 272, 273, 277, 281 (list; graph; refs; listen; history; text; internal format)
OFFSET

0,2

COMMENTS

It appears that a(n) ~ c*n, as n goes to infinity, where c is constant < 2.17. For heuristic argument, see Robert Israel link.

LINKS

Peter J. C. Moses, Table of n, a(n) for n = 0..2499

Robert Israel, Re: a surprising property, SeqFan list, June 01 2015.

MAPLE

T:= <1>:

res:= 0:

for n from 1 to 1000 do

  T:= <1, T[1..-2] + T[2..-1], 2^n>;

  if not ormap(isprime, T) then res:= res, n fi

od:

res; # Robert Israel, Jun 04 2015

PROG

(PARI) isok(n) = {my(s = 0); for (k=0, n, s += binomial(n, k); if (isprime(s), return (0))); return (1); } \\ Michel Marcus, May 31 2015

CROSSREFS

Cf. A007318, A008949, A258126, A258127.

Sequence in context: A041154 A024121 A205144 * A044976 A002642 A032700

Adjacent sequences:  A258480 A258481 A258482 * A258484 A258485 A258486

KEYWORD

nonn

AUTHOR

Vladimir Shevelev, May 31 2015

STATUS

approved

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Last modified October 21 14:04 EDT 2019. Contains 328299 sequences. (Running on oeis4.)