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A060087 Numbers n such that n^2 is a palindromic square with an asymmetric root. 2
1109111, 110091011, 111091111, 10109901101, 10110911101, 11000910011, 11010911011, 11100910111, 1010099010101, 1010109110101, 1011099011101, 1100009100011, 1101009101011, 1110009100111, 100109990011001 (list; graph; refs; listen; history; text; internal format)
OFFSET

1,1

COMMENTS

With 'asymmetric' is meant almost palindromic with a 'core' (pseudo-palindromic). The core '09' when transformed into '1n' (n=-1) makes the base number palindromic. E.g. 1109111 is in fact 11_09_111 -> 11_(10-1)_111 -> 11_1n_111 -> 111n111 and palindromic. Similarly core 099 becomes 10n, core 0999 becomes 100n, etc.

REFERENCES

M. Keith, "Classification and Enumeration of Palindromic Squares," Journal of Recreational Mathematics, 22:2, pp. 124-132, 1990.

LINKS

Table of n, a(n) for n=1..15.

P. De Geest, Subsets of Palindromic Squares

CROSSREFS

Cf. A060088, A007573, A059744, A059745.

Sequence in context: A316481 A253619 A235221 * A229783 A176999 A035613

Adjacent sequences:  A060084 A060085 A060086 * A060088 A060089 A060090

KEYWORD

nonn,base

AUTHOR

Patrick De Geest, Feb 15 2001.

STATUS

approved

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Last modified June 25 18:36 EDT 2019. Contains 324353 sequences. (Running on oeis4.)