A366692 Primes that have more even digits than the next prime.

2, 29, 47, 67, 89, 109, 127, 149, 167, 181, 229, 241, 269, 283, 307, 349, 367, 389, 409, 421, 449, 467, 487, 547, 569, 587, 607, 647, 661, 683, 709, 727, 743, 769, 787, 809, 829, 863, 887, 907, 929, 947, 967, 983, 1009, 1021, 1049, 1087, 1109, 1129, 1163, 1187, 1201, 1229, 1249, 1289, 1307, 1367

Offset

1,1

Links

Robert Israel, Table of n, a(n) for n = 1..10000

Example

a(3) = 47 is a term because 47 is a prime with 1 even digit and the next prime(53) has 0 even digits.

Maple

f:= n -> nops(select(type, convert(n, base, 10), even)):
P:= select(isprime, [2, seq(i, i=3..10000, 2)]):
F:= map(f, P):
P[select(t -> F[t] > F[t+1], [$1..nops(F)-1])];

Mathematica

p = 2; s = {}; Do[If[Count[Mod[IntegerDigits[p], 2], 0]
> Count[Mod[IntegerDigits[q = NextPrime[p]], 2], 0], AppendTo[s, p]]; p = q,
{300}]; s

Crossrefs

Sequence in context: A256472 A330895 A105893 * A059799 A367796 A142969

Adjacent sequences: A366689 A366690 A366691 * A366693 A366694 A366695

Keyword

nonn,base

Author

Zak Seidov and Robert Israel, Oct 16 2023

Status

approved