A174200 The sequence of numbers which, when entered on a standard telephone numeric keypad, produce the letters a thru z. Letters are accessed by one or more presses of a single key.

2, 22, 222, 3, 33, 333, 4, 44, 444, 5, 55, 555, 6, 66, 666, 7, 77, 777, 7777, 8, 88, 888, 9, 99, 999, 9999

Offset

1,1

Comments

Method of entry commonly used on cellular telephones for text-messaging. Not the sequence of a-z used in telephone numbers.

Links

Table of n, a(n) for n=1..26.

Example

To generate the letter 'a', type '2', to generate 'b', type '2' twice, or '22'.

Crossrefs

Sequence in context: A350965 A336894 A037567 * A137109 A002276 A374665

Adjacent sequences: A174197 A174198 A174199 * A174201 A174202 A174203

Keyword

nonn,fini,full

Author

Adam Risi (ajrisi(AT)gmail.com), Mar 11 2010

Extensions

Corrected by Clive Tooth, Jan 28 2016

Status

approved