A167843 Obtuse-angled primes.

113, 127, 137, 139, 149, 157, 167, 179, 199, 211, 223, 227, 229, 233, 239, 257, 269, 277, 311, 331, 337, 347, 349, 359, 367, 379, 389, 421, 431, 433, 443, 449, 457, 467, 479, 499, 521, 541, 557, 569, 577, 599, 631, 641, 643, 653, 661, 677, 733, 743, 751, 761

Offset

1,1

Comments

Primes in A135603.

Primes whose structure of digits represents an obtuse angle. The vertex is an internal digit. In the graphic representation the points are connected by imaginary line segments from left to right.

Links

Michael S. Branicky, Table of n, a(n) for n = 1..914

Prog

(Python) # uses agen() from A135603
from sympy import isprime
g = filter(isprime, agen())
print([next(g) for n in range(1, 53)]) # Michael S. Branicky, Aug 03 2022

Crossrefs

Cf. A134811, A134951, A134971, A135603, A167841, A167842, A167844, A167845, A167846, A167853.

Sequence in context: A345072 A214503 A054033 * A159466 A284598 A060591

Adjacent sequences: A167840 A167841 A167842 * A167844 A167845 A167846

Keyword

base,nonn

Author

Omar E. Pol, Nov 13 2009

Extensions

a(12) and beyond from Michael S. Branicky, Aug 03 2022

Status

approved