A070922 First palindromic prime pyramids with a(1)=2 such that (number of digits in a(n+1)) = (number of digits in a(n)) + 2.

2, 929, 39293, 7392937, 373929373

Offset

1,1

Comments

There are only 2 palindromic prime pyramids beginning with 2 (each one is finite with 5 elements).

References

G. L. Honaker Jr. and C. Caldwell, Palindromic prime pyramids, J. Recreational Mathematics, vol. 30.3, pp. 169-176, 1999-2000.

J.-P. Delahaye, "Pour la science", (French edition of Scientific American), Juin 2002, p. 99.

Links

Table of n, a(n) for n=1..5.

Crossrefs

Cf. A070927.

Sequence in context: A282346 A070967 A070927 * A332192 A258586 A176940

Adjacent sequences: A070919 A070920 A070921 * A070923 A070924 A070925

Keyword

easy,fini,full,nonn,base

Author

Benoit Cloitre, May 24 2002

Status

approved