A303094 Balanced primes of order one ending in 7.

157, 257, 607, 947, 977, 1187, 1367, 1747, 1907, 2287, 2417, 2677, 3307, 3637, 4457, 4597, 4657, 5107, 5387, 5807, 6317, 6367, 6977, 8117, 8747, 9397, 10607, 10657, 11497, 11807, 12497, 12547, 12647, 13177, 13457, 14747, 15467, 15767, 15797, 15907, 16097

Offset

1,1

Links

Table of n, a(n) for n=1..41.

Example

157 = (151 + 157 + 163)/3 = 471/3 and 157 = 15*10 + 7.

Maple

p:=ithprime: a:=n->`if`(add(p(n-k), k=-1..1)=3*p(n) and modp(p(n), 10) = 7, p(n), NULL): seq(a(n), n=3..2000);

Prog

(GAP) P:=Filtered([1..16200], IsPrime);;
a:=Filtered(List(Filtered(List([0..Length(P)-3], k->List([1..3], j->P[j+k])), i->Sum(i)/3=i[2]), m->m[2]), l-> l mod 10=7);

Crossrefs

Intersection of A006562 and A030432.

Cf. A303092, A303093, A303095.

Sequence in context: A142367 A216498 A275317 * A001837 A142581 A140625

Adjacent sequences: A303091 A303092 A303093 * A303095 A303096 A303097

Keyword

nonn,base

Author

Muniru A Asiru, Apr 18 2018

Status

approved