A051276 Nonzero coefficients in one of the 5-adic expansions of sqrt(-1).

2, 1, 2, 1, 3, 4, 2, 3, 3, 2, 2, 4, 1, 3, 2, 4, 4, 3, 4, 4, 1, 2, 4, 1, 4, 1, 1, 3, 1, 4, 1, 4, 2, 1, 1, 3, 3, 2, 2, 4, 4, 2, 4, 3, 1, 2, 4, 3, 3, 3, 3, 1, 3, 1, 1, 3, 3, 4, 1, 3, 3, 3, 4, 2, 2, 2, 1, 4, 1, 1, 4, 4, 2, 1, 2, 3, 4, 4, 4, 2, 2, 1, 3, 1, 3, 2, 4, 2, 1, 4, 3, 4, 3, 1, 2, 1, 3, 3, 3, 1, 1, 3, 1, 2, 2

Offset

0,1

References

Kurt Mahler, Introduction to p-adic numbers and their functions. Cambridge Tracts in Mathematics, 76. Cambridge University Press, Cambridge-New York, 1971. See pp. 35ff.

Links

Table of n, a(n) for n=0..104.

Example

2 + 1*5 + 2*5^2 + 1*5^3 + 3*5^4 + 4*5^5 + 2*5^6 + 3*5^7 + 3*5^9 + 2*5^10 + 2*5^11 + 4*5^13 + 1*5^14 + 3*5^15 + 2*5^16 + 4*5^17 + 4*5^19 + ...

Maple

R:= select(t -> padic:-ratvaluep(t, 1)=2, [padic:-rootp(x^2+1, 5, 200)]):
subs(0=NULL, op([1, 1, 3], R)); # Robert Israel, Mar 04 2016

Prog

(PARI) sqrt(-1+O(5^100))

Crossrefs

Cf. A034935, A048898, A048899, A210850, A210851.

Sequence in context: A133117 A344594 A210850 * A226212 A233439 A256600

Adjacent sequences: A051273 A051274 A051275 * A051277 A051278 A051279

Keyword

nonn,easy,nice

Author

N. J. A. Sloane

Extensions

More terms from Antonio G. Astudillo (afg_astudillo(AT)hotmail.com) and Jason Earls, Jun 15 2001

Name corrected by Robert Israel at the suggestion of Wolfdieter Lang, Mar 04 2016

Status

approved