A051202 - OEIS

A051202

Numbers n such that A005210(n) = 0.

3, 7, 11, 28, 31, 140, 239, 600, 6476, 33172, 64375, 65287, 79051, 97864, 105099, 421335, 710147, 1464192, 3946972, 5423007, 5822348, 6150008, 6297183, 20801744, 22375360, 79009771, 197449588, 266929040, 537524972, 5929856931, 6365146483, 7274986071, 7983314176, 19034311884, 198776542655, 1773302419915

(list; graph; refs; listen; history; text; internal format)

OFFSET

1,1

REFERENCES

Popular Computing (Calabasas, CA), Z-Sequences, Vol. 4 (No. 42, Sep 1976), pp. 12-16.

LINKS

Table of n, a(n) for n=1..36.

Popular Computing (Calabasas, CA), Z-Sequences, continued. Annotated and scanned copy of pages 14, 15, 16, 18 of Vol. 5 (No. 56, Nov 1977).

MAPLE

t1:=[];

M:=200000:

a:=1: b:=1:

for n from 3 to M do c:=abs(2*a+b-n);

if c=0 then t1:=[op(t1), n]; fi;

a:=b; b:=c; od:

[seq(t1[n], n=1..nops(t1))]; # N. J. A. Sloane, Apr 16 2015

PROG

(Python)

A051202_list, a2, a1 = [], 1, 1

for n in range(3, 10**13):

a = abs(a1+2*a2-n)

if a == 0:

A051202_list.append(n)

a1, a2 = a, a1 # Chai Wah Wu, Apr 19 2015

CROSSREFS

Cf. A005210.

Sequence in context: A103798 A093361 A227364 * A211674 A035095 A066674

Adjacent sequences: A051199 A051200 A051201 * A051203 A051204 A051205

KEYWORD

nonn

AUTHOR

David W. Wilson

EXTENSIONS

a(31)-a(34) from Chai Wah Wu, Apr 19 2015

a(35)-a(36) from Chai Wah Wu, May 07 2015

STATUS

approved