A255850 Number of digits in the n-th term of A061844: Squares which remain squares if you decrease every digit by 1.

1, 2, 4, 5, 7, 11, 12, 18, 20, 20, 20, 21, 30, 30, 30, 30, 30, 30, 30, 30, 32, 32, 32, 40, 42, 42, 42, 42, 42, 42, 42, 42, 42, 54, 60, 60, 60, 60, 60, 60, 60, 60, 60, 60, 60, 60, 60, 60, 60, 60, 60, 60, 60, 60, 60, 60, 60, 60, 60, 60, 60, 60, 60, 60, 60, 60

Offset

1,2

Comments

Suggested by W. Appleby in a Number Theory discussion group, cf. link.

Links

Lars Blomberg, Table of n, a(n) for n = 1..78

G. Campbell et al., A six digit problem, Number Theory group on LinkedIn.com, March 2015.

Formula

a(n) = A055642(A061844(n)).

Prog

(PARI) a(n)=#Str(A061844(n)) \\ if A061844 is a function
(PARI) A255850=apply(t->#Str(t), A061844) \\ if A061844 is a vector

Crossrefs

Cf. A061844, A055642, A255851.

Sequence in context: A082741 A288349 A099522 * A108464 A128815 A056527

Adjacent sequences: A255847 A255848 A255849 * A255851 A255852 A255853

Keyword

nonn,base

Author

M. F. Hasler, Mar 10 2015

Extensions

More terms calculated from A061844 by Lars Blomberg, Aug 21 2016

Status

approved