A089317 Prime worms [successive digit differences with absolute value of 4].
151, 373, 95959, 9515959, 159595151, 159595951, 15151595951, 15951595151, 95951515159, 1515159515951, 1515959515951, 1515959595151, 1595159515151, 1595159595151, 9515151515159, 9515159515159, 9515159595959, 9595159515959
Offset: 0
Examples
a(1)=373; first and last digits are 3; abs(3-7)=4; abs(7-3)=4; the worm is 3.
References
- Carlos Rivera's primepuzzles.net, Puzzle 246
Links
- Carlos Rivera, Puzzle 246. The worm
Formula
Select prime numbers having the same first and last digits; if the uniform absolute value of successive digit differences is 4, add to sequence.
Extensions
More terms from David Wasserman, Sep 09 2005