A089315 Prime worms [successive digit differences with absolute value of 3].

14741, 74747, 1414741, 1474141, 14141414141, 14141414741, 14141474741, 14147414741, 14147474141, 74141414147, 1474741414141, 7474141474747, 7474741414747, 14141474141414141, 14147414747474741, 14147474147474741

Offset

0,1

Comments

One of a family of prime worms differing according to the uniform absolute value of successive digit pairs. Sequence checked to 10^9.

This is a subset of A048400. Cf. A089291, A089316-A089317, A048398-A048405.

References

Carlos Rivera's primepuzzles.net, Puzzle 246.

Links

Table of n, a(n) for n=0..15.

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 3, add to sequence.

Example

a(1)=74747 because the number is prime, has identical first and last digits and abs(7-4)=3; abs(4-7)=3; abs(7-4)=3 and abs(4-7)=3. In this number, the worm is 7.

Crossrefs

Sequence in context: A209513 A178587 A178588 * A202314 A236667 A015375

Adjacent sequences: A089312 A089313 A089314 * A089316 A089317 A089318

Keyword

easy,nonn,base

Author

Enoch Haga, Dec 25 2003

Extensions

More terms from David Wasserman, Sep 09 2005

Status

approved