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

Offset: 1

Author

V. Raman, Dec 07 2012

Keywords

• nonn
• base

Examples

			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.
		

Links

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

Crossrefs

Cf. A190639.

Cf. A216287 (lower decade).

Programs

Mathematica

Select[Range[2, 1000], 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 *)

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", ")))

Formula

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

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