Index of the smallest triangular number with digit sum = n-th triangular number.

A068134

Index of the smallest triangular number with digit sum = n-th triangular number.

Terms

    a(0) =0a(1) =1a(2) =2a(3) =3a(4) =7a(5) =12a(6) =56a(7) =109a(8) =368a(9) =1332a(10) =5656a(11) =28248a(12) =140547a(13) =774325a(14) =8485151a(15) =34339452a(16) =397492132a(17) =3996973827a(18) =63229707890

External references