Triangular numbers t such that all the digits needed to write the consecutive triangular numbers from 0 to t fill exactly an equilateral triangle (no holes, no overlaps).

A158030

Triangular numbers t such that all the digits needed to write the consecutive triangular numbers from 0 to t fill exactly an equilateral triangle (no holes, no overlaps).

Terms

    a(0) =0a(1) =3a(2) =10a(3) =21a(4) =153a(5) =210a(6) =378a(7) =496a(8) =820a(9) =1431a(10) =3081a(11) =4656a(12) =8646a(13) =11628a(14) =15051a(15) =17766a(16) =22578a(17) =26335a(18) =32896a(19) =37950a(20) =46665a(21) =53301a(22) =64620a(23) =73153a(24) =87571a(25) =98346a(26) =108345a(27) =113526a(28) =130305a(29) =162735

External references