A219999 - OEIS

A219999

Decades whose prime pattern is the same as prime pattern in the previous decade.

38, 79, 114, 125, 134, 135, 140, 155, 168, 181, 219, 235, 249, 277, 289, 292, 311, 315, 324, 332, 348, 375, 419, 431, 437, 445, 477, 485, 500, 513, 525, 533, 537, 546, 559, 561, 576, 597, 610, 617, 625, 641, 649, 651, 675, 693, 697, 707, 709, 714, 718, 727

(list; graph; refs; listen; history; text; internal format)

OFFSET

1,1

LINKS

V. Raman, Table of n, a(n) for n = 1..10000

FORMULA

a(n) >> n log^2 n.

a(n) = A216287(n) + 1.

EXAMPLE

The primes between 380 and 390 are 383 and 389. The primes in the previous decade are 373 and 379. Therefore 38 is in the sequence.

MATHEMATICA

Select[Range[2, 100], Mod[Prime[Range[PrimePi[NextPrime[10#]], PrimePi[10# + 10]]], 10] == Mod[Prime[Range[PrimePi[NextPrime[10# - 10]], PrimePi[10#]]], 10] (* Alonso del Arte, Dec 07 2012 *)

PROG

(PARI) for(i=2, 1000, if(isprime(10*i-9)==isprime(10*i+1)&&isprime(10*i-7)==isprime(10*i+3)&&isprime(10*i-3)==isprime(10*i+7)&&isprime(10*i-1)==isprime(10*i+9), print1(i", ")))

CROSSREFS

Cf. A190639.

Cf. A216287 (lower decade).

Sequence in context: A044104 A044485 A160846 * A219997 A039421 A043244

Adjacent sequences: A219996 A219997 A219998 * A220000 A220001 A220002

KEYWORD

nonn,base

AUTHOR

V. Raman, Dec 07 2012

STATUS

approved