A237131 Numbers k such that cos(k) = sin(d(1)*d(2)*...*d(q)) where d(1)d(2)...d(q) denotes the decimal expansion of k and the angles are in degrees.

90, 270, 375, 418, 450, 630, 726, 735, 778, 810, 990, 999, 1146, 1170, 1350, 1371, 1386, 1395, 1446, 1494, 1530, 1710, 1731, 1890, 1998, 2070, 2218, 2250, 2394, 2430, 2482, 2610, 2790, 2842, 2898, 2970, 3150, 3171, 3186, 3195, 3312, 3330, 3366, 3375, 3393

Offset

1,1

Links

Table of n, a(n) for n=1..45.

Example

2482 is in the sequence because cos(2482°) = sin(2*4*8*2°)= 0.7880107536067219... (A019861).

Maple

with(numtheory):err:=1/10^10:Digits:=20:for n from 1 to 5000 do:x:=convert(n, base, 10):n1:=nops(x):p:=product('x[i]', 'i'=1..n1):s1:=evalf(cos(n*Pi/180)):s2:=evalf(sin(p*Pi/180)):if abs(s1-s2)<err then printf(`%d, `, n):else fi:od:

Crossrefs

Cf. A237129.

Sequence in context: A235081 A074213 A231961 * A363729 A255784 A250877

Adjacent sequences: A237128 A237129 A237130 * A237132 A237133 A237134

Keyword

nonn,base

Author

Michel Lagneau, Feb 04 2014

Extensions

Name edited by Jon E. Schoenfield, Sep 12 2017

Status

approved