|
Search: id:A068990
|
|
|
| A068990 |
|
Primes which remain prime after each digit is increased by 2. |
|
+0
1
|
|
| 3, 5, 19, 31, 37, 61, 67, 79, 127, 131, 137, 139, 151, 157, 167, 179, 197, 211, 227, 241, 257, 277, 347, 359, 397, 409, 419, 421, 431, 461, 479, 491, 509, 521, 547, 587, 601, 607, 617, 619, 631, 641, 661, 719, 739, 761, 769, 787, 809, 811, 827, 859, 881, 907
(list; graph; listen)
|
|
|
OFFSET
|
1,1
|
|
|
EXAMPLE
|
Increasing each digit of the prime 139 by 2 gives 3511, which is also prime; so 139 is a term of the sequence.
|
|
MATHEMATICA
|
Do[ If[ PrimeQ[ ToExpression[ StringJoin[ ToString /@ (IntegerDigits[Prime[n]] + 2)]]], Print[ Prime[n]]], {n, 1, 500}]
|
|
CROSSREFS
|
Sequence in context: A095826 A058778 A088785 this_sequence A062594 A128027 A128066
Adjacent sequences: A068987 A068988 A068989 this_sequence A068991 A068992 A068993
|
|
KEYWORD
|
base,easy,nonn
|
|
AUTHOR
|
Joseph L. Pe (joseph_l_pe(AT)hotmail.com), Mar 12 2002
|
|
EXTENSIONS
|
Edited and extended by Robert G. Wilson v (rgwv(AT)rgwv.com), Apr 08 2002
|
|
|
Search completed in 0.002 seconds
|
